Electric starting system for an internal combustion engine

ABSTRACT

An electric starting system for an internal combustion engine is provided. The starting system includes a rechargeable battery, a battery receiver, and a starter motor. The rechargeable battery including a battery housing, internal circuitry housed within the battery housing, two voltage output terminals, and an enable terminal. The battery receiver includes a battery receptacle configured to receive the rechargeable battery, two voltage output terminals, and the enable terminal. The starter motor is configured to start the internal combustion engine. The internal circuitry is coupled to the enable terminal and configured to enable and disable an internal switch to provide power to one of the two voltage output terminals, the internal circuitry monitoring at least one internal condition of the rechargeable battery for a fault condition. The internal circuitry disables the internal switch upon detection of the fault condition.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This is a continuation of U.S. application Ser. No. 15/859,852, filedJan. 2, 2018, which is a continuation of U.S. application Ser. No.15/583,753, filed May 1, 2017, now U.S. Pat. No. 9,890,755, which is acontinuation of U.S. application Ser. No. 15/199,682, filed Jun. 30,2016, now U.S. Pat. No. 9,644,595, which is a continuation of U.S.application Ser. No. 14/986,403, filed Dec. 31, 2015, now U.S. Pat. No.9,404,465, which is a continuation of U.S. application Ser. No.14/822,700, filed Aug. 10, 2015, now U.S. Pat. No. 9,228,556, which is acontinuation of U.S. application Ser. No. 14/309,602, filed Jun. 19,2014, now U.S. Pat. No. 9,127,658, all of which are incorporated hereinby reference in their entireties. U.S. application Ser. No. 14/309,602claims the benefit of U.S. Provisional Application No. 61/837,539, filedJun. 20, 2013 and the benefit of U.S. Provisional Application No.61/892,346, filed Oct. 17, 2013, and is a continuation-in-part of U.S.application Ser. No. 13/692,739, filed Dec. 3, 2012, now U.S. Pat. No.8,857,138, which is a continuation-in-part of U.S. application Ser. No.13/289,613, filed Nov. 4, 2011, now U.S. Pat. No. 8,733,072, all ofwhich are incorporated herein by reference in their entireties. U.S.application Ser. No. 14/309,602 is a continuation-in-part of U.S.application Ser. No. 13/913,326, filed Jun. 7, 2013, which claims thebenefit of U.S. Provisional Application No. 61/657,607, filed Jun. 8,2012, and is a continuation-in-part of International Application No.PCT/US2013/035623, filed Apr. 8, 2013, which claims the benefit of U.S.Provisional Application No. 61/625,437, filed Apr. 17, 2012, and is acontinuation-in-part of U.S. application Ser. No. 13/692,739, filed Dec.3, 2012, now U.S. Pat. No. 8,857,138, all of which are incorporatedherein by reference in their entireties. U.S. application Ser. No.14/309,602 is a continuation-in-part of U.S. application Ser. No.14/260,206, filed Apr. 23, 2014, now U.S. Pat. No. 9,220,192, which is acontinuation of U.S. application Ser. No. 13/289,613, filed Nov. 4,2011, now U.S. Pat. No. 8,733,072, all of which are incorporated hereinby reference in their entireties.

BACKGROUND

The present invention generally relates to internal combustion enginesincluding electric starting systems and outdoor power equipment poweredby such engines, such as lawn mowers, snow throwers, portablegenerators, etc. More specifically, the present invention relates tosmall internal combustion engines including electric starting systemspowered by a removable, rechargeable lithium-ion battery.

Outdoor power equipment includes lawn mowers, riding tractors, snowthrowers, pressure washers, portable generators, tillers, log splitters,zero-turn radius mowers, walk-behind mowers, riding mowers, industrialvehicles such as forklifts, utility vehicles, etc. Outdoor powerequipment may, for example use an internal combustion engine to drive animplement, such as a rotary blade of a lawn mower, a pump of a pressurewasher, the auger a snowthrower, the alternator of a generator, and/or adrivetrain of the outdoor power equipment.

Many pieces of outdoor power equipment include engines that are manuallystarted with a recoil starter. To start the engine, the user mustmanually pull a recoil starter rope.

Other pieces of outdoor power equipment include electric startingsystems in which a starter motor powered by a battery starts the engine.Typically, such electric starting systems also include a user-actuatedstarter switch (e.g., a pushbutton or key switch) and a startersolenoid. The starter solenoid is the connection between a low currentcircuit including the starter switch and a high current circuitincluding the starter motor. To start the engine, the user actuates thestarter switch, causing the starter solenoid to close so that thebattery provides starting current to the starting motor to start theengine.

The battery is a lead-acid battery. The battery is secured to theoutdoor power equipment separate from the engine. For example, thebattery may be secured to a mounting plate or deck of a lawn-mower or apressure washer or to the frame of a riding lawn mower or a portablegenerator. The housing of the battery is secured to the outdoor powerequipment by fasteners that require tools (e.g., a wrench or socket) toattach the battery to the outdoor power equipment and to remove orloosen the fasteners so the battery can be removed from the outdoorpower equipment. Also, the battery includes a pair of terminals to whichelectrical leads are attached. Tools are also required to attach andremove the electrical leads to the terminals. Lead-acid batteries arefilled with a liquid electrolyte, typically a mixture of water andsulfuric acid. The electrolyte is corrosive. Lead-acid batteries aretemperature sensitive, which may result in the engine having difficultystarting or not starting at all in cold weather. Also, a lead-acidbattery will run down with the passage of time and not be able toprovide power (i.e., lose charge or become completely discharged). Alead-acid battery may need to be replaced seasonally, removed from theoutdoor power equipment and stored inside, or otherwise maintained orserviced by a user.

SUMMARY

One embodiment of the invention relates to an electric starting systemfor an internal combustion engine including a rechargeable battery, abattery receiver, and a starter motor. The rechargeable batteryincluding a battery housing, internal circuitry housed within thebattery housing, two voltage output terminals, and an enable terminal.The battery receiver includes a battery receptacle configured to receivethe rechargeable battery, two voltage output terminals, and the enableterminal. The starter motor is configured to start the internalcombustion engine. The internal circuitry is coupled to the enableterminal and configured to enable and disable an internal switch toprovide power to one of the two voltage output terminals, the internalcircuitry monitoring at least one internal condition of the rechargeablebattery for a fault condition. The internal circuitry disables theinternal switch upon detection of the fault condition.

Another embodiment of the invention relates to outdoor power equipmentincluding an internal combustion engine, a rotating tool coupled to theengine; a rechargeable battery, a battery receiver, and a starter motor.The rechargeable battery includes a battery housing, internal circuitryhoused within the battery housing, two voltage output terminals, and anenable terminal. The battery receiver includes a battery receptacleconfigured to receive the rechargeable battery, two voltage outputterminals, and the enable terminal. The starter motor is configured tostart the internal combustion engine. The internal circuitry is coupledto the enable terminal and configured to enable and disable an internalswitch to provide power to one of the two voltage output terminals, theinternal circuitry monitoring at least one internal condition of therechargeable battery for a fault condition. The internal circuitrydisables the internal switch upon detection of the fault condition.

Alternative exemplary embodiments relate to other features andcombinations of features as may be generally recited in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will become more fully understood from the followingdetailed description when taken in conjunction with the accompanyingfigures.

FIG. 1 is a perspective view of an internal combustion engine includingan electric starting system powered by a lithium-ion battery, accordingto an exemplary embodiment of the invention.

FIG. 2 is a perspective view of the engine of FIG. 1.

FIG. 2A is an exploded view of the engine of FIG. 1.

FIG. 3 is a top view of the engine of FIG. 1.

FIG. 4 is a right-side view of the engine of FIG. 1.

FIG. 5 is a rear view of the engine of FIG. 1.

FIG. 6 is a perspective view of the battery receiver of the startingsystem of FIG. 1

FIG. 7 is a detail view of a portion of the battery receiver of FIG. 6.

FIG. 8 is a perspective view of the battery receiver of FIG. 6.

FIG. 9 is a detail view of a portion of the battery receiver of FIG. 8.

FIG. 10 is a left-side view of the battery receiver of FIG. 6.

FIG. 11 is a right-side view of the battery receiver of FIG. 6.

FIG. 12 is a rear view of the battery receiver of FIG. 6.

FIG. 13 is a front view of the battery receiver of FIG. 6.

FIG. 14 is a detail view of a portion of the battery receiver of FIG.13.

FIG. 15 is a top view of the battery receiver of FIG. 6.

FIG. 16 is a detail view of a portion of the battery receiver of FIG.15.

FIG. 16A is a perspective view of a battery receiver for a startingsystem, according to an exemplary embodiment.

FIG. 17 is a perspective view of an internal combustion engine includingan electric starting system powered by a lithium-ion battery, accordingto an exemplary embodiment of the invention.

FIG. 18 is a perspective view of an internal combustion engine includingan electric starting system powered by a lithium-ion battery, accordingto an exemplary embodiment of the invention.

FIG. 19 is a perspective view of a lithium-ion battery for use with anelectric starting system of an internal combustion engine, according toan exemplary embodiment of the invention.

FIG. 20 is an exploded view of the lithium-ion battery of FIG. 19.

FIG. 21 is a perspective view from above of the lithium-ion battery ofFIG. 19.

FIG. 22 is a perspective view from below of the lithium-ion battery ofFIG. 19.

FIG. 23 is a perspective view from below of the lithium-ion battery ofFIG. 19.

FIG. 24 is a perspective view from below of the lithium-ion battery ofFIG. 19.

FIG. 25 is a front view of the lithium-ion battery of FIG. 19.

FIG. 26 is a rear view of the lithium-ion battery of FIG. 19.

FIG. 27 is a left-side view of the lithium-ion battery of FIG. 19.

FIG. 28 is a right-side view of the lithium-ion battery of FIG. 19.

FIG. 29 is a top view of the lithium-ion battery of FIG. 19.

FIG. 30 is a bottom view of the lithium-ion battery of FIG. 19.

FIG. 31 is a perspective view of a battery charger for use with alithium-ion battery, according to an exemplary embodiment of theinvention.

FIG. 32 is a perspective of the lithium-ion battery of FIG. 19 attachedto the battery charger of FIG. 31.

FIG. 33 is a schematic diagram of a starter system for an engine,according to an exemplary embodiment of the invention.

FIG. 34 is a schematic diagram of a starter system for an engine,according to an exemplary embodiment of the invention.

FIG. 35 is a schematic diagram of a starter system for an engine,according to an exemplary embodiment of the invention.

FIG. 36 is a schematic diagram of a starter system for an engine,according to an exemplary embodiment of the invention.

FIG. 37 is a circuit diagram of a control system for a battery,according to an exemplary embodiment of the invention.

FIG. 38 is perspective view from above of a blower housing according toan exemplary embodiment.

FIG. 39 is a perspective view from below of the blower housing of FIG.22.

FIG. 40 is another perspective view from below of the blower housing ofFIG. 22.

FIG. 41 is a perspective view of a lawn mower, according to an exemplaryembodiment.

FIG. 42 is a schematic diagram of a starter system for an engine,according to an exemplary embodiment.

FIG. 43 is a perspective view of components of a starter system foroutdoor power equipment according to an exemplary embodiment.

FIG. 44 is a perspective view of an engine assembly, according to anexemplary embodiment.

FIG. 45 is a perspective view of a battery charging station, accordingto an exemplary embodiment.

FIG. 46 is a perspective view of a battery being coupled to an engine,according to an exemplary embodiment.

FIG. 47 is a perspective view of a starter system for the engineassembly of FIG. 44, according to an exemplary embodiment.

FIG. 48 is a front view of a battery for a starter system, according toan exemplary embodiment.

FIG. 49 is a top view of the battery of FIG. 48.

FIG. 50 is a bottom view of the battery of FIG. 48.

FIG. 51 is a left side view of the battery of FIG. 48.

FIG. 52 is a right side view of the battery of FIG. 48.

FIG. 53 is a bottom view of the battery of FIG. 48 with a portion of thehousing removed to show the interior of the battery.

FIG. 54 is a front view of a battery receiver for a starter system,according to an exemplary embodiment.

FIG. 55 is a top view of the receiver of FIG. 54.

FIG. 56 is a bottom view of the receiver of FIG. 54.

FIG. 57 is a cross-section view of the receiver of FIG. 54, taken alongline 57-57.

FIG. 58 is a cross-section view of the receiver of FIG. 54, taken alongline 58-58.

FIG. 59 is a perspective view of a pressure washer according to anexemplary embodiment of the invention.

FIG. 60 is a circuit diagram for a starter system of an engine accordingto another exemplary embodiment of the invention.

DETAILED DESCRIPTION

Before turning to the figures, which illustrate the exemplaryembodiments in detail, it should be understood that the presentapplication is not limited to the details or methodology set forth inthe description or illustrated in the figures. It should also beunderstood that the terminology is for the purpose of description onlyand should not be regarded as limiting.

Internal combustion engines including electric starting systems poweredby a removable, rechargeable lithium-ion battery, as described herein,provide numerous advantages over engines that are manually started andengines including electric start systems powered by a lead-acid battery.Electric starting systems eliminate the need for a manual recoil starterand the need for the user to pull the starter rope to start the engine.Using a removable, rechargeable lithium-ion battery to power theelectric starting system eliminates many of the hassles, inconveniences,and shortcomings of systems powered by the lead-acid batteries. Asdescribed herein, the lithium-ion battery is removable from a batteryreceiver without the use of tools. The relatively lightweightlithium-ion battery is easily attached to and removed from the batteryreceiver by hand. This is greatly simplified from the process ofremoving a lead-acid battery from a piece of outdoor power equipment. Auser must safely disconnect the electrical leads connected to theterminals of the lead-acid battery, which requires the use of tools. Thelead-acid battery must then be removed from its mounting location,typically a frame, plate, or other mounting location separate from theengine. This also requires the use of tools. In several preferredembodiments, the battery receiver is a component of the engine itself sothe lithium-ion battery is mounted to the engine, rather than a locationremote from the engine like a lead-acid battery would be. Systems usinglead-acid batteries may have the lead-acid battery covered or otherwiseout of sight (e.g., under the seat of a riding tractor), requiring theuser to remove or move components to access the lead-battery, anotherstep which may require the use of tools. The ease of removing thelithium-ion battery makes it easier to limit the battery's exposure tocold temperatures than a lead-acid battery (e.g., on a piece of outdoorpower equipment stored in a garage during winter). A user can easilyremove the lithium-ion battery and store it in a heated location (e.g.,inside the user's home), or keep a second lithium-ion battery in aheated location so that the second lithium-ion battery is available foruse if cold temperatures are affecting the operation of the firstlithium-ion battery. Disconnecting, removing, reinstalling, andreconnecting a lead-acid battery using tools in similar cold weatheroperating conditions is a burdensome task not done by a typical user.Also, for pieces of outdoor power equipment used seasonally (e.g., lawnmowers and pressure washers in warm months and snow throwers in coldmonths), a lead-acid battery may be run down, dead, or otherwise at alevel of charge insufficient to start the engine after a season of notbeing used (e.g., starting a lawn mower for the first time afterwinter). A user can either store the lithium-ion battery indoors on thebattery charger, keeping it both charged and at an appropriate operatingtemperature or easily remove the lithium-ion battery from the batteryreceiver without the use of tools, quickly recharge it in the batterycharger, and reattach it to the battery receiver without the use oftools to power the electric starting system and start the engine of theoutdoor power equipment.

The lithium-ion battery described herein recharges quickly even whencompletely depleted of charge. In tests, a lithium-ion battery asdescribed herein completely depleted of charge was charged for oneminute and was able to provide power sufficient to twice start theengine to which it was subsequently attached. The lithium-ion battery asdescribed herein can be fully charged in sixty minutes and at fullcharge can provide fifty starts or more of an engine. The lithium-ionbattery as described herein is able to provide more than ten starts ofan engine after ten minutes of charging.

The lithium-ion battery described herein eliminates concerns related tothe corrosive electrolyte of a lead-acid battery, simplifying handlingof the battery by the user.

The ability to install the lithium-ion battery without the use of toolsand including the battery receiver as a component of the engine itselfsimplifies assembly of the engine into a piece of outdoor powerequipment by an original equipment manufacturer (“OEM”). There is noneed for the OEM to use tools to attach the lithium-ion battery to theoutdoor power equipment, unlike with a lead-acid battery, and also noneed to use tools to connect electrical leads to the terminals of thebattery. Also, fewer parts may be required. For example, the wiringharness including the electrical leads attached to the lead-acid batterymay be eliminated or simplified in its design and/or routing.

The ease of removing and recharging the lithium-ion battery as describedherein also increases end-user comfort with outdoor power equipment notincluding a manual starting system (e.g., a recoil starter). Because thelithium-ion battery is easily removed without tools and quicklyrecharged to a charge state sufficient to start the engine, the end usercan be confident in being able to start the engine in most circumstances(e.g., absent any issues with the starting system and other enginecomponents other than a dead battery). In preferred embodiments, thelithium-ion battery described herein includes a display that visuallyindicates to the user the battery's level of charge. An electricalstarting system powered by a lead-acid battery that is not able to startthe engine can be incredibly frustrating for the end user (e.g, becausethe lead-acid battery has insufficient charge to start the engine).There is no quick and easy way to determine the level of charge in thelead-acid battery and, if necessary, no quick and easy way to replace orrecharge the lead-acid battery. A depleted lead-acid battery needs to bedisconnected from the electrical leads with tools, removed from theoutdoor power equipment with tools, and be properly disposed of. The enduser then must acquire a new lead-acid battery, almost certainly needingto take a trip to the store to do so, install the new lead-acid batterywith tools, and connect the electrical leads to the new lead-acidbattery with tools.

Referring to FIGS. 1-5, an internal combustion engine 1000 isillustrated according to an exemplary embodiment. The internalcombustion engine 1000 includes an engine block 1002 having a cylinder1004, a piston 1006, and a crankshaft 1008. The piston 1006 reciprocatesin the cylinder 1004 along a cylinder axis 1010 to drive the crankshaft1008. The crankshaft 1008 rotates about a crankshaft axis 1012. As shownin FIG. 2A, the engine 1000 includes fuel system 1001 for supplying anair-fuel mixture to the cylinder 1004 (e.g., a carburetor, an electronicfuel injection system, etc.), an air filter assembly 1003, a cylinderhead assembly 1005, a muffler assembly 1007, a fuel tank assembly 1009,and a flywheel and fan assembly 1011. In the illustrated embodiment, thecylinder 1004 and the cylinder axis 1010 are oriented horizontally(i.e., a horizontal cylinder engine). In some embodiments, the cylinder1004 and the cylinder axis 1010 can be oriented vertically (i.e., avertical cylinder engine) or at an angle (i.e., a slanted engine). Insome embodiments, the engine includes multiple cylinders, for example, atwo cylinder engine arranged in a V-twin configuration.

The engine 1000 also includes an electric starting system 1014. Theelectric starting system 1014 includes a starter motor 1016, a batteryreceiver 1018, and a removable, rechargeable lithium-ion battery 1020.The starter motor 1016 is electrically coupled to the lithium-ionbattery 1020 to be powered by the lithium-ion battery 1020. Whenactivated in a response to a user input (e.g., via a key switch, a pushbutton, a bail start system, a trigger start system for a pressurewasher, other automatic start system, etc.), the starter motor 1016rotates the crankshaft 1008 to start the engine. The starter motor 1016is selectively coupled to the crankshaft 1008 (e.g., by a movable piniongear that selectively engages a flywheel ring gear) so that the startermotor 1016 may be decoupled from the crankshaft 1008 (i.e., does notrotate with the crankshaft 1008 after the engine 1000 has beensuccessfully started). As illustrated, the starter motor 1016 isattached to the engine block 1002.

Referring to FIGS. 6-18, the battery receiver 1018 is illustratedaccording to an exemplary embodiment. The battery receiver 1018 includesa receptacle 1022 (port, socket, pocket, etc.) configured to receive thelithium-ion battery 1020. The receptacle 1022 includes three maleterminals 1024, 1026, and 1028 configured to couple with correspondingfemale terminals of the lithium-ion battery 1020. The receptacle 1022includes a second set of three male terminals 1030, 1032, and 1034configured to be coupled to corresponding terminals of a wiring harness,which is electrically coupled to the starter motor and any otherelectrical components of the engine 1000 and/or the piece outdoor powerequipment including the engine that are powered by or send signals(data, information, etc.) to and/or from the lithium-ion battery 1020.Each of the terminals 1024, 1026, and 1028 is electrically coupled to acorresponding one of the terminals 1030, 1032, and 1034. Two pairs ofthe terminals (e.g., terminal pair 1024 and 1030 and terminal pair 1028and 1034) are used to complete an electrical circuit between the startermotor 1016 and the lithium-ion battery 1020 (e.g., as a positiveterminal pair and a ground terminal pair). These two pair of terminalsmay be referred to as voltage output terminals. The third pair of theterminals (e.g., terminal pair 1026 and 1032) is used to transmit asignal (e.g., an enable signal as described herein) to and/or from thelithium-ion battery 1020. This third pair of terminals may be referredto as data terminals or as the enable terminals. A guide 1036 (wall,protrusion, etc.) is positioned on either side of each of the terminals1024, 1026, and 1028. Each guide 1036 is received by a correspondingaperture in the lithium-ion battery and helps to guide the terminals1024, 1026, and 1028 into the corresponding female terminals of thelithium-ion battery 1020. The guides 1036 extend outward from a wall1038 of the receptacle 1022 to a distance greater than that of theterminals 1024, 1026, and 1028. The enable terminal 1026 extends to adistance less than the voltage output terminals 1024 and 1028. Thishelps to ensure that lithium-ion battery 1020 is not able to power thestarter motor 1016 except when the lithium-ion battery 1020 is properlysecured (fully inserted, fully seated, properly inserted, properlyseated, properly installed) in the receptacle 1022. Unless thelithium-ion battery 1020 is properly secured, the lithium-ion battery1020 cannot provide power to the starter motor 1016, even with thevoltage output terminals 1024 and 1028 electrically connected tocorresponding voltage output terminals of the lithium-ion battery 1020.The lack of connection to the enable terminal 1026 prevents an enablesignal needed for the lithium-ion battery 1020 to provide power to thestarter motor 1016 from reaching the lithium-ion battery 1020.

The receptacle 1022 is defined by a floor 1040, sidewalls 1042, and anend wall 1044. The receptacle 1022 is open on one end 1046 to allow thelithium-ion battery 1020 to be slid into the receptacle 1022 from theside. The sidewalls 1042 are connected by the end wall 1044. Aprotrusion or rail 1048 extends inward from each sidewall 1042 and issized to be received by a corresponding slot in the lithium-ion battery1020. Each rail 1048 extends forward from the end wall 1044 toward theopen end 1046.

The sidewalls 1042 may each include an angled end portion 1050 proximatethe open end 1046 such that the open end 1046 has a width that isgreater than the width of the lithium-ion battery 1020 and of theremainder of the receptacle 1022. The angled end portions 1050facilitate the insertion of the lithium-ion battery 1020 into thereceptacle 1022 through the open end 1046. The angled end portions 1050also provide access for a user to actuate the push buttons found on thesides of the lithium-ion battery 1020.

The floor 1040 is an offset body that includes the wall 1038 (a verticalstep or shoulder). The wall 1038 may contact a corresponding wall of thelithium-ion battery 1020 to limit the travel of the lithium-ion battery1020 relative to the receiver 1018. The wall 1038 separates two portionsof the floor 1040, the upper portion 1052 and the lower portion 1054.The lower portion 1054 includes a latching region 1056 (strike plate,latching portion, locking region, locking portion) configured to receivea corresponding latch of the lithium-ion battery 1020 to secure thelithium-ion battery to the battery receiver 1018. The latching region1056 includes apertures 1058 that each are configured to receive andcorrespond to a protrusion of the latch of the lithium-ion battery 1020.

In some embodiments, the receptacle 1022 is configured to protect theterminals 1024, 1026, and 1028 from environmental hazards. For example,the floor 1040 may slope away from the terminals 1024, 1026, and 1028 todirect moisture away from the terminals 1024, 1026, and 1028. Accordingto other exemplary embodiments, the terminals may be orientedhorizontally or the terminals of the battery may be vertical andinterface with terminals provided in an elevated portion of the receiversuch that any moisture that enters the space between the battery and thereceiver flows away from the terminals. The battery receiver 1018 and/orother portions of the engine 1000 proximate the receptacle 1022 mayinclude features (e.g., channels, drain holes, weep holes, slopedsurfaces, etc.) that direct moisture and debris away from the terminals1024, 1026, and 1028.

As illustrated, the battery receiver 1018 is a portion of an enginehousing 1060 (blower housing, cowl, cover, etc.) The battery receiver1018 includes an air intake 1062. The air intake 1062 includes multipleapertures 1064 (openings, slots, etc.) that allow air to enter theengine housing (e.g., air drawn into the engine housing by a flywheel orblower fan for use to air cool the engine). The apertures 1064 alsolimit the ability for debris such as grass clippings to pass through theair intake 1062. As illustrated, the battery receiver 1018 is formed asa generally dome-shaped body that is configured as a cover or screen ofthe engine. The battery receiver 1018 may be separate from a base 1066(remainder) of the engine housing 1060. As illustrated, the batteryreceiver 1018 is secured to the base 1066 by threaded fasteners. Inother embodiments, for example as illustrated in FIG. 16A, the batteryreceiver 1018 is integrally formed (e.g., molded) with the base 1066 ofthe engine housing 1060.

As illustrated, the battery receiver 1018 is positioned relative to therest of the engine 1000 at the location typically occupied by a recoilstarter in a manually-started engine. With this positioning, theelectric starting system 1014 replaces the recoil starter in a way thatis intuitive to the user by placing the battery receiver 1018 and thelithium-ion battery 1020 in the location where the user expects to findthe equipment (i.e., the recoil starter) used to start a typicalmanually-started engine. This positioning places the battery receiver1018 above the crankshaft 1008 with the crankshaft axis 1012 extendingthrough a portion of the battery receiver 1018. The flywheel is locatedbelow the battery receiver 1018. Eliminating the recoil starter reducesthe engine operating temperature (e.g., the oil temperature) byimproving air flow into the cooling system (e.g., the blower housing).For example, replacing the recoil starter with the battery receiver 1018and the lithium-ion battery 1020 can reduce the engine operatingtemperature by between 10 and 20 degrees Fahrenheit (5.6 degrees and11.1 degrees Celsius) in expected operating conditions. Reducing theengine operating temperature can help to reduce oil deterioration,overheating, and other failure modes related to high temperatures. Inother embodiments, the receptacle 1022 is incorporated into a batteryreceiver having a different shape or form appropriate to the mountinglocation for that receiver relative to the other components of theengine 1000. For example, the battery receiver for ahorizontally-shafted single-cylinder engine or for a two-cylinder enginemay be located at a different portion of the engine housing than thevertically-shafted single-illustrated engine 1000 as shown. Referring toFIG. 17, a horizontally-shafted single-cylinder internal combustionengine 3000 is illustrated according to an exemplary embodiment. Thelithium-ion battery 1020 is selectively attached to a battery receiver3018. As illustrated, the battery receiver 3018 is a portion of theengine housing 3060. Referring to FIG. 18, a V-twin two-cylinderinternal combustion engine 4000 is illustrated according to an exemplaryembodiment. The lithium-ion battery 1020 is selectively attached to abattery receiver 4018. As illustrated, the battery receiver 4018 is aportion of the engine housing 4060. In other embodiments, the batteryreceiver is not a component of the engine itself and is instead mountedto the outdoor power equipment at a location remote from (separate from,spaced apart from), the engine 1000. An electrical connection (e.g., awiring harness) is used to electrically connect such a battery receiverto the starter motor 1016 and any other required electrical componentsof the outdoor power equipment. For example, for a riding tractor,riding lawn-mower, snow thrower, or zero-turn mower, the batteryreceiver may be a component of a dashboard or other user-control panel.

Referring to FIGS. 19-30, the lithium-ion battery 1020 is illustratedaccording to an exemplary embodiment. The lithium-ion battery 1020 isnot equivalent to a lithium-ion battery for use with cordless powertools (e.g., a drill). For example, the lithium-ion battery 1020 mayinclude fewer lithium-ion battery cells than a power tool battery and isintended for less frequent cycling at lower run times than a power toolbattery (e.g., used to start an engine, not used to power frequentrunning of a drill motor for relatively long durations). The operationof the lithium-ion battery 1020 requires an output of relatively highcurrent (e.g., 200 Amps) over a relatively short discharge time (e.g.,10 milliseconds). A lithium-ion battery for use with a power tool orportable computing device (e.g., a laptop computer) provides an outputof a relatively low current over a relatively long discharge time.Additionally, a power tool lithium-ion battery is “always on” so that itis always able to provide power to the tool. In a preferred embodimentdescribed in more detail below, the lithium-ion battery 1020 is only onwhen it is receiving an enable input indicating a need to start theengine. Without the enable input, the lithium-ion battery 1020 does notprovide any power to the electric starting system 1014. This allows thelithium-ion battery 1020 to be removed from the receptacle 1022 afterthe engine 1000 is successfully starter. For example, a user could startthe engine 1000 with a lithium-ion battery 1020 having a relatively lowcharge and then remove and recharge the lithium-ion battery 1020 whileusing the outdoor power equipment. In a preferred embodiment, thelithium-ion battery 1020 is rated at 10.8 Volts (V) and 1.5 Amp-hours(Ah).

As shown in FIG. 20, the lithium-ion battery 1020 includes one or morelithium-ion cells 1068 electrically coupled together. As illustrated,three lithium-ion cells 1068 are used, though more or fewer may be usedin different embodiments. Each lithium-ion cells 1068 is formed as anelongated body having a longitudinal axis (e.g., a cylindrical,cylinder, or cylindrical roll style lithium-ion cells). All threelithium-ion cells 1068 are oriented in the same direction, the cell axis1070. The three lithium-ion cells 1068 are secured as a pack 1072 sothat the entirety of the pack 1072 (including all three lithium-ioncells 1068) moves as a single integral unit. This prevents the threelithium-ion cells 1068 from moving independently to one another.Movement of the pack 1072 as a single unit helps to reduce failure modesfor the lithium-ion battery 1020 related to vibration, as will beexplained in more detail herein.

The lithium-ion battery 1020 also includes processing electronics 1074(controller, processing circuit, etc.) In a preferred embodiment, theprocessing electronics 1074 includes a processor 1076 (microprocessor)and a memory device 1078. The processor 1076 can be implemented as ageneral purpose processor, an application specific integrated circuit(ASIC), one or more field programmable gate arrays (FPGAs), a group ofprocessing components, or other suitable electronic processingcomponents. The memory device 1078 (e.g., memory, memory unit, storagedevice, etc.) is one or more devices (e.g., RAM, ROM, Flash memory, harddisk storage, etc.) for storing data and/or computer code for completingor facilitating the various processes, layers and modules described inthe present application. The memory device 1078 may be or includevolatile memory or non-volatile memory. The memory device 1078 mayinclude database components, object code components, script components,or any other type of information structure for supporting the variousactivities and information structures described in the presentapplication. According to an exemplary embodiment, The memory device1078 is communicably connected to processor via processing circuit andincludes computer code for executing (e.g., by processing circuit and/orprocessor) one or more processes described herein. In a preferreddevice, the processing electronics 1074 implements one or more processesto protect the lithium-ion battery 1020 (e.g., prevents operationoutside of a range of appropriate operating temperatures), to optimizeperformance of the lithium-ion battery 1020, and to optimize the life ofthe lithium-ion battery 1020.

The lithium-ion battery 1020 further includes a display 1080 forproviding information to a user. In the illustrated embodiment, thedisplay 1080 consists of four light sources 1082. In a preferredembodiment, each light source 1082 is a light-emitting diode (LED). Inother embodiments, more or fewer light sources may be included. In otherembodiments, the display 1080 is a LCD or other appropriate displayscreen. In some embodiments, an audible device (e.g, a speaker) is usedin addition to or in place of the display 1080 to provide information toa user. A user interface 1084 (e.g., a pushbutton, switch, button,touchscreen, etc.) is actuated by the user to activate the display 1080.Once activated, the display 1080 provides a battery charge levelindication to the user by turning on one or more of the light sources1082. In some embodiments, the display 1080 is deactivated after apredetermined amount of time passes after the user actuates the userinterface 1084. In other embodiments, the display 1080 is only activatedwhile the user interface 1084 is actuated. In a preferred embodiment,all four light sources 1082 being lit indicates more than 78% chargelevel, three lights sources 1082 being lit indicates more than 55%charge level, two light sources 1082 being lit indicates more than 33%charge level, one light source 1082 being lit indicates more than 10%charge level, one blinking or flashing light source 1082 indicates lessthan 10% charge level, and all four light sources 1082 blinking orflashing indicates an error (e.g., an overcurrent state). In someembodiments, the display 1080 is omitted.

A battery housing 1086 contains and supports the lithium-ion cells 1068and the processing electronics 1074. The housing 1086 also supports thedisplay 1080 and the user interface 1084. As illustrated, the housing1086 is formed by two primary pieces, a top half or portion 1088 and abottom half or portion 1090, though other constructions are possible.The housing 1086 has a top side 1092, a bottom side 1094, a front side1096, a back side 1098, a left side 1100, and a right side 1102. Theoverall dimensions of the housing 1086 correspond to those of thereceptacle 1022 so that the lithium-ion battery 1020 can be received bythe receptacle 1022 and attached to the battery receiver 1018. In apreferred embodiment, the housing 1086 is a sealed enclosure that isconfigured to protect the electrochemical cells by preventingenvironmental contaminants (e.g., moisture, plant debris, salt, dust,etc.) from passing into the interior of the housing 1086. The housing1086 provides a rugged structure that is able to withstand impact duringoperation of the outdoor power equipment (e.g., impacts from branches ortrunks when operating a lawn mower). The housing 1086 can be formed froma material that is resistant to liquid or vaporized fuel (e.g.,polyethylene terephthalate or PET) to prevent fuel from passing into theinterior of the housing 1086.

An aperture or slot 1104 is formed in the left side 1100 and the rightside 1102 proximate the back side 1098. The slots 1104 include an openend at the back side 1098 and an opposite closed end. Each slot 1104 issized to receive the corresponding rail 1048 of the receptacle 1022.Contact between the closed end of the slots 1104 and the correspondingends of the rails 1048 functions as a stop to limit the travel of thelithium-ion battery 1020 into the receptacle 1022.

As shown in FIGS. 24, 26-28, and 30, the bottom side 1094 of the housing1086 is an offset body that mirrors the floor 1040 of the receptacle1022. The bottom side 1094 includes an upper portion 1106 and a lowerportion 1108 separated by a wall 1110. Contact between the wall 1110 ofthe lithium-ion battery 1020 and the corresponding wall 1038 of thereceptacle 1022 functions as a stop to limit the travel of thelithium-ion battery 1020 into the receptacle 1022.

A latch 1112 (lock, locking member, latching member) is pivotallycoupled to the housing 1086. As shown in FIG. 23, in a latched position(secured, locked, engaged, extended etc.), a latching portion 1114 ofthe latch 1112 extends through an aperture 1116 (opening) through thebottom side 1094 of the housing 1086 and is retracted through theaperture 1116 into the interior of the housing 1086 in a releaseposition (unlatched, unsecured, unlocked, disengaged, retracted, etc.).A body portion 1118 of the latch 1112 (FIG. 20) remains in the interiorof the housing 1086. The latch 1112 is mechanically coupled to a pair ofpush buttons, a right push button 1120 and a left push button 1122. Eachpush button extends through an aperture in a corresponding side of thehousing. The push buttons 1120 and 1122 are biased outward from theinterior of the housing 1086 to an extended position (secured, locked,engaged, latched, etc.) A spring 1124 or other biasing member or biasingmembers bias the push buttons 1120 and 1122 to the extended position. Asshown in FIG. 24, the push buttons 1120 and 1122 are movable inwardtoward the interior of the housing 1086 to a depressed position(retracted, released, unsecured, unlocked, disengaged, etc.). Themechanical coupling between the push buttons 1120 and 1122 is such thatthe push buttons being in the extended position causes the latch 1112 tobe in the latched position (FIG. 23) and moving both push buttons 1120and 1122 to the depressed position causes the latch 1112 to be in therelease position (FIG. 24). This mechanical coupling also causes thespring 1124 to bias the latch 1112 to the latched position. The pushbuttons 1120 and 1122 are able to move separately from one another, buteach push button 1120 and 1122 must be in its depressed position for thelatch to completely be in the release position. This arrangement helpsto avoid accidental unlatching (unsecuring, release, unlocking, etc.) ofthe lithium-ion battery 1020 from the receptacle 1022 when only one ofthe push buttons 1120 and 1122 is depressed. This helps to prevent thelithium-ion battery 1020 from unwanted unlatching when impacted by anobject or obstacle (branch, trunk, wall, shrub, rock, etc.) when in useon a piece of outdoor power equipment because it is unlikely that bothpush buttons 1120 and 1120 will be simultaneously actuated by anunwanted impact with an object of obstacle when using the outdoor powerequipment. The latching portion 1114 includes one or more protrusions,as illustrated a transverse wall 1126 and three legs 1128 that extendsubstantially perpendicular to the wall 1126.

Four female terminals 1130, 1132, 1134, and 1136 are located within thebottom side 1094 of the housing 1086. The female terminals 1130, 1132,1134, and 1136 are configured to couple with the corresponding maleterminals of a receptacle, for example male terminals 1024, 1026, and1028 of the receptacle 1022 of the battery receiver 1018 or maleterminals of the receptacle of a battery charger.

A pair of the terminals (e.g., terminals 1130 and 1134) are used tocomplete an electrical circuit between the starter motor 1016 and thelithium-ion battery 1020 (e.g., as a positive terminal and a groundterminal). This pair of terminals may be referred to as voltage outputterminals. The other two terminals (e.g., terminals 1132 and 1136) mayeach be used to transmit a signal (e.g., an enable signal as describedherein) to and/or from the lithium-ion battery 1020. This second pair ofterminals may be referred to as data terminals. In particular, one ofthe terminals (e.g., terminal 1132) may be referred to as the enableterminal and is used to receive an enable input signal as describedherein. In a preferred embodiment, each of the female terminals 1130,1132, 1134, and 1136 is formed as a pair of opposed springs that receiveand hold a male terminal of the lithium-ion battery 1020. The opposedsprings exert opposing forces transverse to the longitudinal axis of themale terminal, which helps to reduce wear of the male terminals and makea secure electrical connection between the female terminal and the maleterminal.

The terminals 1130, 1132, 1134, and 1136 are positioned within slots orapertures 1140 formed in the bottom side 1094. Each aperture 1140 has anopen end in the wall 1110 and an open end in the upper portion 1106 andis sized to receive a corresponding male terminal. Additional apertures1142 are formed in the bottom side, each with an open end in the wall1110 and an open end in the upper portion 1106. Each aperture 1142 issized and positioned to receive one of the guides 1036 of the receptacle1022. The interaction between the apertures 1142 and the guides 1036help to guide the lithium-ion battery 1020 into the receptacle 1022 andensure proper connections between the male terminals of the receptacle1022 and the female terminals of the lithium-ion battery 1020.

In alternative embodiments, the lithium-ion battery 1020 can include afew as two male terminals (i.e., two voltage output terminals) or morethan four male terminals. In some embodiments, two pairs of terminalsare configured as voltage output terminals. For example, the first pairof voltage output terminals could provide a voltage (e.g., 10 V)sufficient to start the starter motor 1016 and the second pair ofvoltage output terminals could provide a voltage (e.g., 3 V) sufficientto power one or more other electric components of the engine 1000 or theoutdoor power equipment powered by the engine 1000 (e.g., a light sourceor processing electronics). As another example, the first pair ofvoltage output terminals could provide a voltage (e.g., 12 V) sufficientto start the starter motor 1016 and be grouped with an enable terminalto control activation of the lithium-ion battery 1020 and the secondpair of voltage output terminals could provide a continuous voltage(e.g., 12 V) not dependent on the state of the enable signal to theenable terminal to power one or more electronic components of the engine1000 or the outdoor power equipment powered by the engine 1000 otherthan starter motor 1016.

According to other exemplary embodiments, the lithium-ion battery 1020may further include additional ports or connectors. For example, thebattery may include a universal serial bus (USB) port that may be usedas an input to receive power to charge the lithium-ion cells 1068 or asan output to power or charge another device (e.g., a mobile phone, etc.)from the lithium-ion cells 1068.

To attach the lithium-ion battery 1020 to the battery receiver 1018, theuser slides the lithium-ion battery 1020 back side first into thereceptacle 1022 through the open end 1046. The front end of each rail1048 is received in the corresponding slot 1104 of the lithium-ionbattery 1020, helping to guide the lithium-ion battery 1020 into thereceptacle 1022 and to position the lithium-ion battery 1020 within thereceptacle 1022. Each of the apertures 1142 of the lithium-ion battery1020 then receive the corresponding guide 1036 of the receptacle,further helping to guide the lithium-ion battery 1020 into thereceptacle and positioning the female terminals 1130, 1132, and 1134 ofthe lithium-ion battery 1020 to receive the male terminals 1024, 1026,and 1028 of the receptacle 1022. The voltage output terminals 1024 and1130 and 1028 and 1134 are electrically connected before the enableterminals 1026 and 1132. Contact between the wall 1038 of the receptacle1022 and the wall 1110 of the lithium-ion battery and contact betweenthe front ends of the rails 1048 of the receptacle 1022 and the closedends of the slots 1104 of the lithium-ion battery 1020, and contactbetween the end wall 1044 of the receptacle 1022 and the back side 1098of the lithium-ion battery 1020 stop (limit, halt) insertion of thelithium-ion battery 1020 into the receptacle 1022 and align the latch1112 of the lithium-ion battery 1020 and the latching region 1056 of thereceptacle 1022. When these points of physical contact between thelithium-ion battery 1020 and the receptacle are made, the lithium-ionbattery 1020 is properly secured (fully inserted, fully seated, properlyinserted, properly seated, properly installed) in the receptacle 1022.These points of physical contact between the lithium-ion battery 1020and the receptacle 1022 and the longitudinal dimensions of the enableterminals 1026 and 1132 are arranged so that the enable terminals 1026and 1132 are not electrically connected unless these points of physicalcontact are made between the lithium-ion battery 1020 and the receptacle1022, thereby preventing the lithium-ion battery 1020 from powering thestarter motor 1016 because the lithium-ion battery 1020 cannot receivethe enable signal. The latch 1112 is biased to latched position toautomatically engage the latching region 1056, thereby attaching(securing, locking) the lithium-ion battery 1020 to the battery receiver1018. In some embodiments, the latch 1112 engages the latching region1056 with an audible sound (e.g., a “click”). With the latch 1112 in thelatched position, the latching portion 1114 engages the latching region1056 of the receptacle 1022 to attach the lithium-ion battery 1020 tothe battery receiver 1018. In the latched position of the latch 1112,the wall 1126 and legs 1128 of the latching portion 1114 are received bycorresponding apertures 1058 of the latching region 1056. In the releaseposition of the latch 1112, the wall 1126 and the legs 1128 are movedout of the apertures 1058, unattaching (unsecuring, unlocking,releasing, disengaging) the lithium-ion battery 1020 from the batteryreceiver 1018 and allowing the lithium-ion battery 1020 to be removedfrom the receptacle 1022 by reversing the above steps. The latch 1112 ismoved to the release position by moving each push button 1120 and 1122to its depressed position. In this way, the lithium-ion battery 1020 isremovably attached to the battery receiver 1018 and the push buttons1120 and 1122 and latch 1112 allow a user to selectively attach andremove the lithium-ion battery 1020 to the battery receiver 1018 withoutthe use of tools.

Vibrations caused by the operation of an engine and the operation of thepiece of outdoor power equipment that the engine powers can potentiallycause the loss of the electrical connections between one or more of theterminals of the lithium-ion battery 1020 and the terminals of thereceptacle 1022. These vibrations can also potentially damage thelithium-ion cells 1068 or other sensitive components of the lithium-ionbattery 1020 or the battery receiver 1018. These possible negativeeffects caused by vibrations inherent in the operation of the engine andthe outdoor power equipment that the engine powers can be reduced byselecting an appropriate orientation of the cell axis 1070 of alithium-ion battery 1020 attached to the battery receiver 1018. Thiscell axis orientation is dependent on the orientation of the receptacle1022 of the battery receiver 1018. To reduce the possible negativeeffects caused by vibrations, the cell axis 1070 should not be parallelto (in the same direction) an axis representative of the primarydirection of vibrations of the engine or vibrations of the piece ofoutdoor power equipment to which the engine will be attached (i.e., aprimary vibration axis). The vibrations of the engine or the outdoorpower equipment will likely not be purely linear in a single direction.However, analyzing the vibrations of the engine or the specific piece ofoutdoor power equipment identifies the primary vibration axis for thatspecific engine or piece of outdoor power equipment. For example, thesingle-cylinder vertically-shafted engine illustrated as the engine 1000has a primary vibration axis parallel to the cylinder axis 1010. Asanother example, when the engine 1000 is used to power a lawn-mowerhaving an unbalanced blade driven by the crankshaft 1008, the primaryvibration axis is parallel to the crankshaft axis 1012. In a preferredembodiment, the battery receiver 1018 is positioned so that the cellaxis 1070 of an attached lithium-ion battery 1020 is as far out ofparallel with the primary vibration axis as possible, that is, orientedtransverse to (perpendicular to, at an angle of 90 degrees relative to)the primary vibration axis to minimize the possible negative effects ofthe vibrations. For example, as shown in FIG. 3, the engine 1000 has aprimary vibration axis parallel to the cylinder axis 1010 and the cellaxis 1070 of the lithium-ion battery 1020 is transverse to the cylinderaxis 1010 and therefore also transverse to the primary vibration axis.As another example, as shown in FIG. 17, the horizontally-shafted engine3000 has a primary vibration axis parallel to the cylinder axis 3010 andthe cell axis 1070 of the lithium-ion battery 1020 is transverse to thecylinder axis 3010 and therefore also transverse to the primaryvibration axis. Using a Cartesian coordinate system to describe theseaxes, the cylinder axis 1010 can be considered the x-axis, the cell axis1070 can be considered the y-axis, and the crankshaft axis 1012 can beconsidered the z-axis. The primary vibration axis parallel to thez-axis, the battery receiver 1018 could be positioned so that the cellaxis 1070 is parallel to the y-axis (as illustrated in FIG. 3) or sothat the cell axis 1070 is parallel to the x-axis, with bothorientations being transverse to the primary vibration axis.Orientations other than transverse for the cell axis 1070 relative tothe primary vibration axis provide some reduction of the negativeeffects of the vibrations as compared to the cell axis 1070 and theprimary vibration axis being parallel to one another. Two axes“substantially transverse” to one another are positioned at 90 degreesplus or minus 10 degrees relative to one another. An axis is“substantially vertical” when within plus or minus 10 degrees ofvertical for an engine in a normal operating position. An axis is“substantially horizontal” when within plus or minus 10 degrees ofhorizontal for an engine in a normal operating position. In someembodiments, the cell axis 1070 is positioned at an angle of at least 15degrees relative to the primary vibration axis. In some embodiments, thecell axis 1070 is positioned at an angle of at least 45 degrees relativeto the primary vibration axis.

Referring to FIGS. 31-32, a battery charger 1200 is illustratedaccording to an exemplary embodiment. The battery charger 1200 isconfigured to charge lithium-ion batteries as described herein (e.g.,the lithium-ion battery 1020). The battery charger 1200 includes areceptacle 1201 similar to the receptacle 1022 of the battery receiver1018 described above. The lithium-ion battery 1020 is removably attachedto the battery charger 1200 without the use of tools in a manner similarto that described above for the battery receiver 1018.

The receptacle 1201 of the battery charger 1200 includes four maleterminals 1202, 1204, 1206, and 1208 rather than the three terminals ofthe receptacle 1022. Two terminals (e.g., terminals 1202 and 1206) areconfigured as voltage output terminals as described above and correspondto the female voltage output terminals of the lithium-ion battery 1020.The other two terminals (e.g., terminals 1204 and 1206) are configuredas data terminals as described above. The extra fourth terminal (e.g.,terminal 1206) relative to the receptacle 1022 is used to transmitstatus and/or error data from the lithium-ion battery 1020 to thebattery charger 1200.

The battery charger 1200 includes a power cord 1210 configured to beconnected to a source of electrical power (e.g., an electrical outletconnected to a grid or generator). The type of plug on the cord 1210will vary depending on the market in which the battery charger 1200 willbe used (e.g., the United States uses a different plug configurationthan Europe, the United Kingdom uses a different plug configuration thanother countries in Europe, etc.). The cord 1210 is electricallyconnected to a transformer which converts the input electrical power toan electrical power form appropriate for charging the lithium-ionbattery 1020 via the voltage output terminals 1202 and 1206.

The battery charger 1200 also includes processing electronics 1212(controller, processing circuit, etc.) In a preferred embodiment, theprocessing electronics 1212 includes a processor 1214 (microprocessor)and a memory device 1216. The processor 1214 can be implemented as ageneral purpose processor, an application specific integrated circuit(ASIC), one or more field programmable gate arrays (FPGAs), a group ofprocessing components, or other suitable electronic processingcomponents. The memory device 1216 (e.g., memory, memory unit, storagedevice, etc.) is one or more devices (e.g., RAM, ROM, Flash memory, harddisk storage, etc.) for storing data and/or computer code for completingor facilitating the various processes, layers and modules described inthe present application. The memory device 1216 may be or includevolatile memory or non-volatile memory. The memory device 1216 mayinclude database components, object code components, script components,or any other type of information structure for supporting the variousactivities and information structures described in the presentapplication. According to an exemplary embodiment, The memory device1216 is communicably connected to processor via processing circuit andincludes computer code for executing (e.g., by processing circuit and/orprocessor) one or more processes described herein. In a preferreddevice, the processing electronics 1212 implements one or more processesto control charging of the lithium-ion battery 1020, to protect thelithium-ion battery 1020 (e.g., prevents operation outside of a range ofappropriate operating temperatures), to optimize performance of thelithium-ion battery 1020, to optimize the life of the lithium-ionbattery 1020, and to provide a user with information about thelithium-ion battery 1020. The battery charger 1200 includes atemperature sensor 1217 configured to detect when the ambienttemperature is outside of an acceptable operating range (i.e., below acold threshold temperature or above a hot threshold temperature).

The battery charger 1200 further includes a display 1218 for providinginformation to a user. In the illustrated embodiment, the display 1218consists of five light sources 1220. In a preferred embodiment, eachlight source 1220 is a light-emitting diode (LED). In other embodiments,more or fewer light sources may be included. In other embodiments, thedisplay 1218 is a LCD or other appropriate display screen. In someembodiments, an audible device (e.g, a speaker) is used in addition toor in place of the display 1218 to provide information to a user. In apreferred embodiment, the display 1218 is always activated when alithium-ion battery 1020 is attached to the battery charger 1200. In apreferred embodiment, the display 1080 of the lithium-ion battery 1020is also always activated when the lithium-ion battery 1020 is attachedto the battery charger 1200. In a preferred embodiment, the first lightsource 1220 lit to provide red light indicates that the lithium-ionbattery 1020 is charging normally, the second light source 1220 lit toprovide a green light indicates that the lithium-ion battery 1020 isfully charged, the third light source 1220 lit to provide a red lightindicates that a temperature detected by the temperature sensor 1217 isoutside the acceptable operating range and that the lithium-ion battery1020 will not accept a charge, the fourth light source flashing orblinking a red light and the fifth light source flashing or blinking agreen light indicates that the lithium-ion battery 1020 will not chargeand should be replaced. In some embodiments, the display 1218 isomitted.

In some embodiments, the lithium-ion battery 1020 includes maleterminals and the receptacle 1022 of the battery receiver 1018 and thereceptacle 1201 of the battery charger 1200 include female terminals. Inother embodiments, the lithium-ion battery and the receptacles use otherappropriate types of paired electrical connections to electricallyconnect the lithium-ion battery to the receptacles.

In a preferred embodiment, an engine (e.g., the engine 1000), alithium-ion battery (e.g., the lithium-ion battery 1020), and a batterycharger (e.g., the battery charger 1200) are packaged as an internalcombustion engine and battery charging system. For example, such asystem could be sold to OEMs for use in various pieces of outdoor powerequipment.

For embodiments of the engine 1000 using a magneto or spark ignitionsystem, extra energy in the form of ignition sparks or pulses can beharvested and stored in a capacitor or other energy storage device(e.g., battery) for use to trickle charge the lithium-ion battery 1020attached to the battery receiver 1018. Though a spark based ignitionsystem is discussed as an example other types of ignition systems arepossible. The excess energy of the ignition system may also besufficient to power the other electrical components of the lithium-ionbattery 1020 or the engine 1000. After the engine 1000 is started, thereis a relatively abundant amount of excess energy that can be harvestedto charge the lithium-ion battery 1020. For example, the energy from thetwo positive pulses or sparks of a four-cycle magneto ignition systemcan yield about one amp of current. Other types of ignition systems alsoprovide waste energy that could be harvested to power the electronicgovernor system. In a four-cycle magneto ignition system there is awaste spark on the exhaust stroke of the cylinder. In such a system, thetwo positive pulses or sparks and the waste negative pulse or sparkcould all be harvested. Control circuitry associated with the engine1000 or outdoor power equipment powered by the engine 1000 (e.g.,control circuitry included in the lithium-ion battery 1020, controlcircuitry included in the battery receiver 1018, other engine or outdoorpower equipment control circuitry, etc.) can include an outlet capableof trickle charging the lithium-ion battery 1020 through the use ofignition primary pulses, in accordance with yet another exemplaryembodiment. The running state/rpms of the engine 1000 are conventionallymonitored by reading ignition primary pulses, wherein each ignitionprimary has a sequence of positive and negative pulses. The positiveprimary pulses are not needed/used for production of a spark to fire theengine, so the energy/current from the positive primary pulses may beused for other uses (e.g., monitoring the rpms). In this instance, thereis enough energy from the positive primary pulses to both monitor theengine's rpms and trickle charge the lithium-ion battery 1020. Thus,after the engine 1000 has run for a certain period of time (e.g., 12-15minutes), the positive primary pulses provide enough energy to replenishthe energy used during one starting/cranking cycle, thereby eliminatingthe need for the user to recharge lithium-ion battery 1020 via othermeans after running engine 1000 a certain amount of time.

Referring now to FIG. 33, a low current enable circuit 902 for a startersystem 900 is shown according to an exemplary embodiment utilizinginternal battery circuitry and an external low current switch to engagethe starter system 900 and control the high current circuit 908connecting the starter motor 906 to the battery 904. The starter motor906 may therefore be stopped and started without the use of costly highcurrent switch provided in series between the battery 904 and thestarter motor 906 and configured to handle the full motor current (e.g.,more than 100 Amps). The starter system may further include a secondaryactivation device such as a bail (not shown) as described above.

The battery 904 includes a pair of primary terminals (e.g., contacts,pins, etc.), shown as a first terminal 910 (e.g., positive terminal) anda second terminal 912 (e.g., negative terminal, ground, etc.). Thebattery 904 is coupled to the starter motor 906 via the first terminal910 and the second terminal 912 to form the high current circuit 908powering the starter motor 906. The battery 904 further includes a thirdterminal 914 (e.g., enable terminal, enable pin, enable contact, etc.),which may be positioned relative to the first terminal 910 and thesecond terminal 912 similar to the auxiliary terminal 832 of the battery800 in FIG. 50. The third terminal 914 is coupled to circuitry 916provided within the battery housing 918. The internal circuitry 916monitors the internal conditions of the battery 904 for fault conditions(e.g., overvoltage, undervoltage, overcurrent, overtemperature, etc.).

According to an exemplary embodiment, the internal circuitry 916includes a transistor 920 (e.g., a MOSFET) which enables or disables aswitch 922 to selectively provide power to the first terminal 910 of thebattery 904. The transistor 920 is connected to the third terminal 914.If the third terminal 914 is connected to the second terminal 912 (e.g.,connected to ground), the switch 922 closes and connects the firstterminal 910 to the internal cells of the battery 904 to provide powerto the first terminal 910 and to the starter motor 906 or another loadconnected to the battery 904. If the third terminal 914 is disconnectedfrom the second terminal 912, the switch 922 is opened and the battery904 is disabled.

The low current enable circuit 902 connects the third terminal 914 tothe second terminal 912. The low current enable circuit 902 is a lowcurrent circuit and may include a switch 924 provided in series betweenthe third terminal 914 and the second terminal 912 allowing a user toselectively enable and disable the battery 904. According to anexemplary embodiment, the switch 924 is a low cost, low current switchactuated with a user interface such as a push-button (e.g., a startbutton, a bail, etc.) or actuated automatically (e.g., by a pressureswitch or sensor, a flow switch or sensor, a combination of the twoetc.) as in a trigger-started pressure washer (e.g., pressure washer2010 described below). The user may depress the button to close theswitch 924 and complete the low current enable circuit 902. The internalswitch 922 is then closed and current flows from the battery 904 to themotor 906 through the high current circuit 908. Once the starter motor906 has started the engine, the user may release the button to open theswitch 924 and break the low current enable circuit 902 between thethird terminal 914 and the second terminal 912. The internal switch 922is opened and the battery 904 is disabled. The low current enablecircuit 902 may be overridden by the internal circuitry 916 such thatthe user may not enable the battery 904 with the switch 924 if there aninternal fault condition is detected. In another embodiment, the switch924 may not be a non-momentary switch (e.g., latching switch) and mayremain closed after the user releases the button.

Referring now to FIG. 34, in another embodiment, the third terminal 914may not be positioned proximate the first terminal 910 and the secondterminal 912 but may be positioned elsewhere on the battery 904. Forexample, the third terminal 914 may be positioned on an opposite side ofthe battery 904 relative to the first terminal 910 and the secondterminal 912.

Referring now to FIG. 35, in another exemplary embodiment, the lowcurrent enable circuit 902 may be utilized to turn on and off anycontinuous duty electrical load connected to the battery 904 in parallelwith the starter motor 906. Such a continuous load may be, for example,a lamp 930 (e.g., console lighting, headlamps, etc.), a radio 932, aheater 934, etc.

Referring now to FIG. 36, in another exemplary embodiment, the startersystem 900 may include an external battery control module 940 (e.g., amodule including an electrical control circuit). The module 940 may bepositioned in various locations on or around the engine. For example,the module may be a distinct component (e.g., electronic control 520shown in FIG. 43), the module may be component of an engine controlleror control circuitry, the module may be mounted on the engine, or themodule may be mounted to the battery receiver (e.g., battery receiver802). The control module 940 includes a switch 942 provided along thelow current enable circuit 902. The switch 942 may be provided insteadof or in addition to the switch 924 actuated by the user. According toan exemplary embodiment, the switch 942 may be a low current electronicswitching device (e.g., MOSFET, transistor, hall effect sensor, reedswitch, etc.). The switch 942 may be controlled automatically with acontrol input. For example, the control module 940 may receive an engineRPM input 944 and open the switch 942 when the engine RPM input 944indicates that the engine has reached a predetermined RPM threshold,thereby breaking the low current enable circuit 902 and disabling thebattery 904 to stop the starter motor 906.

Referring now to FIG. 37 an electrical control circuit 950 for a batterycontrol module 940 is shown according to an exemplary embodiment. Insome embodiments, the circuit 950 contains essentially all analog parts.In some embodiments, the circuit 950 is implemented as “non-programmablecircuitry” that consists of analog or digital hard circuitry that doesnot utilize a microcontroller or software. It is believed thatembodiments in which the controls are implemented as non-programmablecircuitry including discrete components may be less expensive thanembodiments implemented with microcontrollers or using software. Suchnon-programmable circuitry embodiments do not include a microcontroller.In other embodiments, the circuit 950 is implemented in amicrocontroller or using software. In some embodiments, the circuit 950is configured to detect when a bail closes (or opens) a switch (e.g.,the switch 924).

Referring to FIGS. 38-40, a blower housing 870 (e.g., engine housing) isshown according to an exemplary embodiment. As shown in FIG. 39, theblower housing 870 includes a mating surface 872 to which the batteryreceiver 802 is coupled. The mating surface 872 surrounds an air inletopening 873. The air inlet opening 873 allows air to enter the blowerhousing 870. Air is drawn through the openings 840 in the batteryreceiver 802 into the blower housing 870. The battery receiver 802 canbe coupled to mating surface 872 in various appropriate ways includingwith mechanical fasteners (e.g., bolt, screw, etc.), with snap-fitfasteners, gluing, epoxying, welding, etc. The mating surface 872includes an opening 874 that allows an electrical connecting component(e.g., the terminals 860 and 862 of the receiver 802, a plug on a wiringharness extending from the terminals 860 and 862, etc.) to extendthrough the mating surface 872 so that the battery receiver 802 can beelectrically coupled to another component of the engine or outdoor powerequipment powered by the engine (e.g., an engine controller, controlcircuitry, etc.). As shown in FIG. 40, the opening 874 leads to channel876 for routing wires or a wiring harness. A sidewall 878 extending fromthe mating surface 872 separates the channel 876 from an interiorchamber 880 defined by the blower housing 870. A fan and/or other movingengine parts (e.g., crankshaft, flywheel) may be positioned in or nearthe interior chamber 880. The sidewall 878 protects the wires or wiringharness in the channel 876 from the moving engine parts. Without thesidewall 878 and the channel 876, the wires or wiring harness couldbecome entangled with and damaged by the moving engine parts.

In some embodiments, as shown in FIGS. 38-40, a socket 882 is positionedin the opening 874. The socket 882 couples to the electrical connectingcomponent (e.g., the terminals 860 and 862 of the receiver 802, a plugon a wiring harness extending from the terminals 860 and 862, etc.) ofthe battery receiver. For example, the terminals 860 and 862 arereceived by corresponding openings 884 in the socket 882. The socket 882is also coupled to an electrical connecting component of the othercomponent of the engine or outdoor power equipment to which the batteryreceiver is electrically coupled. For example, a wiring harness mayinclude a plug that is coupled to the socket 882. The wiring harness maybe used to electrically couple the battery receiver to the othercomponent of the engine or outdoor power equipment. As another example,the socket 882 may be the plug of a wiring harness. The socket 882 isthe electrical connection point between the battery receiver and theother component of the engine or outdoor power equipment to which thebattery receiver is electrically coupled (e.g., module 940 describedbelow). Assembly of the engine is simplified by including the socket 882in the blower housing 870.

In some embodiments, the battery receiver 802 is mounted to the engine(e.g., on the blower housing 870) so that the effects of the vibrationsof the engine on the engagement of the battery 800 to the batteryreceiver 802, including the engagement of the battery terminals 830 and832 to the receiver terminals 860 and 862, are minimized. For example,the installation direction in which the battery 800 is slid into orotherwise engages the battery receiver 802 is not the same direction asthe engine vibrations. Assuming that the engine vibrations can beconsidered to oscillate along one or vibration axes (i.e., a major axis,one or more minor axes, a combined axis that sums the effect of all theengine vibrations), the battery receiver 802 should be arranged so thatthe installation direction of the battery 800 is different than thevibration axis (e.g., the installation direction is perpendicular to themajor axis, the installation direction is perpendicular to the combinedaxis, the installation direction is at an angle to one or more of thevibration axes). The location at which the battery receiver 802 ismounted to the engine may also be chose to minimize the effects of theengine vibrations. For example, the battery receiver 802 may be mountedso that the battery terminals 830 and 832 and the receiver terminals 860and 862 may, to the extent possible, be aligned with drive shaft of theengine or other source of engine vibrations. As another example, thebattery receiver 802 may be mounted remote from the drive shaft of theengine or other source of engine vibrations. The battery receiver 802may be mounted via a damper (shock-absorber, dash-pot, etc.) or othercomponent that minimizes or absorbs the engine vibrations. Similarly,the battery receiver 802 may be mounted to the engine or elsewhere onthe outdoor power equipment to minimize the effect of the vibrations ofthe outdoor power equipment as a whole (e.g., the vibrations caused bythe operation of the outdoor power equipment, not just those caused bythe engine).

The various combinations of batteries 800 (e.g., batteries of differentcapacities) and battery receivers 802 (e.g., receivers that can receiveone or more sizes of battery) helps original equipment manufacturers(“OEMs”) more easily incorporate an electric start system into theirproducts. For example, the battery 800 and the battery receiver 802 mayreplace a typical recoil starter and use the same amount of space andsimilar connections as a typical recoil starter. Also, by providing abattery 800 and receiver 802 with additional terminals for future use,OEMs have flexibility in how to use and incorporate the battery 800 andreceiver 802 into their products. Providing standardized batteries 800and battery receivers 802 allows OEMs to more quickly install thesecomponents when manufacturing their products and increases theirfamiliarity with how to incorporate these components into theirproducts.

Typically the outdoor power equipment includes a brake mechanism thatselectively prevents or stops rotation of the tool. The brake may stop aflywheel of the engine, correspondingly stopping the crankshaft androtating tool coupled to the power takeoff of the crankshaft.

Starting the braked outdoor power equipment may be cumbersome, requiringrelease of the brake followed by activation of the engine. For lawnmowers and other types of outdoor power equipment, release of the brakemay include rotating a bail to draw an inner-wire of a Bowden cable thatlifts the brake mechanism. Then, activation of the engine typicallyfurther includes manually pulling a recoil starter rope or activating anelectric starter for the engine. A need exists for a less-cumbersome andfaster process to start the outdoor power equipment.

Furthermore, the outdoor power equipment may include the engine mountedto a frame or a base plate. If an electric starter is included, thestarter motor is typically connected to an interface on the handle ofthe outdoor power equipment so that the operator may activate thestarter motor while standing in an operational position, such as behindthe handle. During assembly of the outdoor power, a power source,control circuitry, and wiring associated with the starter motor arecoupled to the handle, the frame, and the engine, the attachment ofwhich may be a time-consuming and labor-intensive process. A need existsfor an engine having a starter motor that facilitates efficient assemblyof the outdoor power equipment.

Referring to FIG. 41, outdoor power equipment, in the form of a lawnmower 110, includes an internal combustion engine 112 coupled to arotary tool, such as the blade in a deck 114 of the lawn mower 110, anauger, a saw, tines, a drill, a pump, or other rotary tools. In someembodiments, the lawn mower 110 further includes wheels 116 and arearward extending handle 118 designed to be pushed by an operatorwalking behind the lawn mower 110. In other contemplated embodiments,the outdoor power equipment may be in the form of a rotary tiller, apressure washer, a snow thrower, a lawn tractor or riding mower, anedger, a portable generator, or other equipment, with a correspondingpowered tool, such as tines, a pump, an auger and impeller, analternator, a drive train, or other tools.

Still referring to FIG. 41, the lawn mower 110 includes a startersystem. According to an exemplary embodiment, the starter systemincludes an electric motor 120 that is selectively coupled to the engine112 such that the electric motor 120 is configured to rotate thecrankshaft of the engine 112 to start the engine 112, and is thenconfigured to disengage once the engine 112 is running. In someembodiments, the motor 120 is fastened to the engine 112, such as beingmounted on top of or to a side of the engine 112. Gearing (e.g., gearreduction, transmission) may extend between the motor 120 and thecrankshaft of the engine 112, or the motor 120 may be connected directlyto the crankshaft of the engine 112.

According to an exemplary embodiment, an operator may engage the startersystem via the handle 118 of the lawn mower 110. In some embodiments,the handle 118 includes a lever 122, button, toggle, or other interfacethat the operator may use to command the starter system to start theengine 112. In some embodiments, the command is relayed from the handle118 via a linkage 124, such as an electric wire transmitting anelectrical signal, a Bowden cable communicating a mechanical signal, oranother type of linkage. In contemplated embodiments, a transmitter andstart button are coupled to the handle (e.g., clipped on, integrallymounted with), and the starter system includes an integrated receiverconfigured to receive commands wirelessly provided by the transmitter tostart the engine. According to an exemplary embodiment, the command fromthe operator is received directly or indirectly by the motor 120, andthe motor 120 rotates the crankshaft to start the engine 112.

In some embodiments, the starter system is integrated with a bail 126 ofthe lawn mower 110. A brake mechanism (e.g., friction brake, ignitioninterrupt switch or circuit, etc.) may be holding the blade or othertool, locking the crankshaft of the engine 112, or otherwise preventingoperation of the power equipment. When the operator actuates the bail126 to release the brake mechanism from rotating members (e.g., blade,crankshaft, power takeoff, flywheel, blower fan, etc.) of the lawn mower110, the action simultaneously actuates the motor 120 to start theengine 112. As such, releasing of the brake mechanism synergisticallyalso starts the engine 112, easing operation of the lawn mower 110 orother outdoor power equipment by reducing the steps necessary foractivation.

In some embodiments, the lawn mower 110 includes an interlock 128 (e.g.,lock-out device, signal interrupt) to prevent release of the brake andengagement of the motor 120. According to an exemplary embodiment, theoperator must release the interlock 128 before the bail 126 can beoperated to engage the motor 120 to start the engine 112. Differenttypes of mechanical and electrical interlocks may be used in varyingcontemplated embodiments to prevent inadvertent release of the brake andstarting of the engine, such as when a user moves the power equipmentinto or out of a garage or storage shed by grabbing the handle, or ifthe bail is unintentionally bumped. Furthermore, engagement of theinterlock 128, in some embodiments, is also configured to preventinadvertent release of the brake when the handle 118 is being foldedover the deck 114 to put the lawn mower 110 in a storage configuration.

In general, integration of the starter system with a handle of outdoorpower equipment allows the operator to start the engine from the rear ofthe outdoor power equipment, such as several feet from the powered toolof the outdoor power equipment (e.g., snow thrower auger, lawn mowerblades). Further, the integration supports an electric starting systemfor a walk behind mower that can be engaged by a user without actuationof a key or push-button. In other embodiments, the starter system mayinclude a start button or other interface to engage the starter systemthat is located on the engine or elsewhere. For example, in contemplatedembodiments, such an interface may include a smart phone application orremote control that wirelessly provides a start command or authorizationcode to a receiver coupled to the outdoor power equipment.

According to an exemplary embodiment, the starter system furtherincludes an energy storage device 130 (e.g., electrical storage device)and a controller 132. The energy storage device 130 may include one ormore batteries, capacitors, or other devices. When the operator engagesthe starter system, the linkage 124 communicates the command to startthe engine directly or indirectly to the controller 132, whichelectrically connects the energy storage device 130 to power the motor120. In some embodiments, the controller 132 is coupled to a governor ofthe engine 112 (see, e.g., speed sensor 420 as shown in FIG. 42), anddisengages the motor 120 (e.g., cuts power to the motor 120, high-sideswitching of the battery power source, low-side switching of the groundside of the circuit) when the engine 112 is running at a sufficientspeed.

In some embodiments, the motor 120, the energy storage device 130, andthe controller 132 are fastened directly to the engine 112, which may beconfigured for efficient assembly of outdoor power equipment using theengine 112. As such, the starter system in some embodiments may comefully assembled with the engine 112 and ready for connection to alinkage configured to provide a signal from the handle (e.g., linkage124). In some embodiments, an interface (e.g., start button, toggle,switch, etc.) for starting the engine is positioned on the engineitself, and no additional connections are necessary—the manufacturerneed only attach the engine to the deck or corresponding feature andattach the tool to the power takeoff of the engine. In any such case,considerable time and effort may be saved during the manufacturingprocess and a potential source of manufacturing difficulty may beremoved (i.e., that associated with the fastening and electricalconnection of the components of the starter system during assembly ofthe outdoor power equipment). In still other embodiments, some or all ofthe starter assembly may be fastened to the deck of a lawn mower orcorresponding feature of other power equipment.

Referring to FIG. 42, outdoor power equipment 410 (shown schematically)includes an engine 412 and a powered tool 414 (e.g., rotary blade)driven by the engine 412. In some embodiments, a motor 416 is coupled tothe engine 412, and the powered tool 414 is coupled to a power takeoff418 of the engine 412. A speed sensor 420 (e.g., governor) may becoupled to the engine 412 to regulate the speed of the engine 412. Also,a brake 422 may be coupled to a rotary member of the outdoor powerequipment 410, such as the flywheel of the engine, the power takeoff 418of the engine, etc., to stop the engine as well as the associatedpowered tool.

In some embodiments, the outdoor power equipment 410 includes a handle424 having a release mechanism 426, where the release mechanism 426 isconfigured to allow a user to release the brake 422 from the handle 424.The release mechanism 426 may allow a user to release the brake 422 byengaging the bail (or other element) with a linkage connected to thebrake 422, or by disengaging an element blocking movement of the bail.The handle 424 may be coupled to the engine 412 and tool 414 directly,or via an intermediary member (e.g., deck 114 as shown in FIG. 41). Theengine 412 may further include a battery 428 (e.g., a lithium-ionbattery) for powering the motor 416 and a control system 430 foroperating the motor 416.

According to an exemplary embodiment, the control system 430 isconfigured to receive inputs associated with the release mechanism 426.In some embodiments, when the release mechanism 426 is actuated torelease the brake 422, the release mechanism 426 triggers a switch 432,which provides to the control system 430 a signal that is indicative ofthe release of the brake 422. The signal may be provided via amechanical linkage, wirelessly, a hardwired electrical connection, orotherwise. In some embodiments, the control system 430 then actuates themotor 416 to start the engine 412 or uses the information in controllogic configured to start the engine as a function of the status of thebrake and other factors. As such, operation of the release mechanism 426may simultaneously provide a start signal to the control system 430 aswell as release the brake 422. No additional operations to start theengine 412 may be required.

According to an exemplary embodiment, the control system 430 isconfigured to receive additional inputs from the speed sensor 420 oranother component of the engine 412 (e.g., ignition circuit). The speedsensor 420 or other component provides the control system 430 withinformation associated with the speed of the engine 412. When the engine412 is running at a sufficient speed, the control system 430 thendisengages the motor 416 (e.g., turns off, disconnects, cuts power to,etc.).

In contemplated embodiments, the control system 430 associated with thestart system may receive additional or different inputs used to controlstarting of the engine, such input from a sensor configured to indicatewhether the outdoor power equipment has moved recently. Movement of anaxle or wheels of such outdoor power equipment may trigger a sensor thatprovides a signal to the control system. The signal, in combination withan electric timer providing time-related context for the movement, mayserve as an additional indicator that the operator intends to activatethe engine. In contemplated embodiments, the control system 430 includesa timer and is configured to deactivate the motor if the engine has notstarted within a predetermined amount of time. In some contemplatedembodiments, the control system 430 includes a temperature sensor and isconfigured to prime the engine with an automated primer pump or adjustthe choke or throttle plate if ambient temperature is above or below apredetermined temperature, if a portion of the engine is above or belowa predetermined temperature, or if the difference between ambient andengine temperature is above or below a predetermined amount. Incontemplated embodiments, the control system 430 may also provide asignal output to the operator, such as a visible indicator on a displaycoupled to the handle or engine, or an audible alert. In some suchembodiments, the signal output may include as an error message, alow-fuel message, a replace-oil message, or another such message.

Referring to FIG. 43, components of a system 510 include a brake cable512 (e.g., Bowden cable) and a brake pad 514 for an associated engine ofoutdoor power equipment. According to an exemplary embodiment, the brakecable 512 is configured to be coupled to the bail of a handle of outdoorpower equipment (see, e.g., bails 126, 212, and 312 as shown in FIG. 1).When an operator activates the bail, the brake cable 512 moves a pivot516 coupled to the brake pad 514. The brake pad 514 then releases,allowing the engine associated with the system 510 to drive a poweredtool of the outdoor power equipment.

According to an exemplary embodiment, the engine associated with thesystem 510 further includes a starter system including a switch 518, anelectronic control 520, a battery 522 (e.g., a lithium-ion battery), andan electric starter motor 524. When the operator activates the bail tolift the brake pad 514, the pivot 516 simultaneously activates theswitch 518. The switch 518 then provides a signal to the electroniccontrol 520 that the brake pad 514 has been lifted and that theelectronic control 520 may start the engine associated with the system510 with the electric starter motor 524. The electronic control 520 thenconnects the electric starter motor 524 to the battery 522. The switch518 may be a switch already associated with the brake, but used toprovide signals to both an actuator of the brake and the starter system(e.g., ignition ground), or the switch 518 may be an additional switchsolely used for the starter system.

Still referring to FIG. 43, the electronic control 520 includeshard-wired circuitry and is configured to receive additional inputs fromthe engine associated with the system 510. In some embodiments, theadditional inputs include an indication of the speed of the engineassociated with the system 510 from a governor or other component of theengine (e.g., electrical pulses from the ignition system). Theadditional inputs may include a current state of the engine associatedwith the system 510, such as whether the engine associated with thesystem 510 is running, etc. The starter system is also coupled to aground 526.

Referring to FIGS. 44-47, an engine 610 includes an exhaust 612, a fueltank 614, an engine cover 616, an air intake 618 for combustionprocesses, an air intake 620 for cooling the engine, and a startersystem having an energy storage device, such as a battery 622 (e.g., alithium-ion battery), a capacitor, multiple batteries or capacitors, oranother energy storage device. Applicants note that the engine 610 ofFIGS. 44-47 mirrors the engine 112 of FIG. 41, and both aresingle-cylinder, four-stroke cycle, vertically-shafted, small engines.Other engine types and designs may be used, such as engines that arehorizontally-shafted, two- or more cylindered, diesel powered,cold-weather structured, etc.

Although shown as proximate to the fuel tank 614 and exhaust 612 inFIGS. 44 and 46-47, the energy storage device (e.g., the battery 622)may be positioned elsewhere on the exterior and/or in an internal portof the engine 610. In some embodiments, where the battery 622 issensitive to high temperature, it may be preferred to position thebattery 622 away from the exhaust 612, which may become hot duringoperation of the engine 610. According to an exemplary embodiment, thebattery 622 may be positioned in the path of the air intake 618 suchthat it does not excessively obstruct the flow of air through the airintake 618 into the engine. The air drawn in through the air intake 618may therefore be utilized to aid in cooling of the battery 622.

According to an exemplary embodiment, the energy storage device isconfigured to power a starter motor (see, e.g., motor 120 as shown inFIG. 41) integrated with the engine 610. In some embodiments, the energystorage device may be further configured to power other systems of theengine 610, such as an engine control unit (ECU) having controlcircuitry coupled to sensors or detectors integrated with the engine(e.g., brake release, fuel-level detector, ignition-fouling detector,governor, etc.).

According to an exemplary embodiment, the energy storage device is thebattery 622, which is rechargeable. As shown in FIG. 45, the battery 622may be charged at a charging station 624 or may include a charging portintegrated with the battery (e.g., battery pack with charging port toreceive a connection from a wire coupled to an outlet or the chargingstation). The battery 622, in other embodiments, may alternatively plugdirectly into a wall outlet, or the charging station may be wall mountedor plug directly into a wall outlet.

In contemplated embodiments, the starter motor is configured to drawpower from the engine 610, such as during periods of lesser loads on theengine. The starter motor is then driven by the engine 610 to provide anelectric output. The electric output may then be routed by the ECU orotherwise to the charge the energy storage device. Such a system may beparticularly useful for an engine driving an alternator of a portablegenerator, where the alternator may temporarily be powered by the energystorage device to start the engine and then, once the engine hasstarted, the alternator may be used to recharge the energy storagedevice.

In contemplated embodiments, an appropriately sized energy storagedevice (e.g., the battery 622) may be configured to provide power toother electrical systems of the outdoor power equipment besides thestarter system, such as lighting systems (e.g., headlights, dash lights,indicator lights, etc.), sound devices, or other on-board electronicsystems. The energy storage device may then be used instead of alead-acid battery or an alternator and regulator coupled to the engine.

In some embodiments, the energy storage device is or includes a bank ofcapacitors, where the capacitors are configured to charge and releaseelectrical energy in a relatively short (e.g., less than 10 seconds),high-powered output. In some such embodiments, some of the capacitors ofthe bank are coupled with one another in groups (e.g., series orparallel), and the groups are configured to output sequentially in timewith respect to one another. Accordingly, the capacitors arespecifically configured to be able to power the motor to start theengine 610 without much additional energy storage capacity so as to berelatively compact in size and inexpensive. Use of capacitors may alsoallow for faster charging when compared to batteries, such as fastercharging on the charging station 624 (FIG. 45).

Referring to FIG. 46, the battery is configured to be inserted (e.g.,dropped, lowered, placed) into a receiver, shown as a receiving port 626integrated with the engine. Integrating the receiving port with theengine reduces the assembly burdens for manufacturing outdoor powerequipment, as disclosed above. However in contemplated embodiments, thereceiving port may not be integrated with the engine. For example, FIG.45 shows a charging station 624 or charging port, which may be similarto such a port on a deck of the engine.

In some embodiments, the battery 622 has a cross section forming anisosceles trapezoid, triangle, diamond, or other wedge shape, or shapehaving a narrower lower portion 628 relative to an upper portion 630 incontact with the receiving port 626. The receiving port 626 is contoured(e.g., V-shaped, U-shaped, etc.) to receive the battery 622, which maybe guided into position by interfacing with the contours of thereceiving port 626 and gravity.

In some embodiments, the battery 622 includes slots or grips 632 forlifting and holding the battery 622. A locking mechanism, such as a hookor latch may snap into place when the battery 622 is inserted into thereceiving port 626 and hold the battery 622 in the receiving port 626.Pinching the grips 632 together may release the locking mechanism toallow removal of the battery 622 from the receiving port 626.

According to an exemplary embodiment, the starter system furtherincludes a switch 636 (e.g., toggle, lever, key) that is integrated withthe battery 622, the receiving port 626, or elsewhere on the engine 610.As shown in FIGS. 46-47, the switch 636 may rotate from an off position(FIG. 46), where the battery 622 is not electrically connected tocomponents of the engine 610 (e.g., starter motor, ECU), to an onposition (FIG. 47), where the battery 622 is electrically connected tothe components. In other embodiments, rotation of the switch 636 also oralternatively engages the locking mechanism to hold the battery 622 inthe receiving port 626. In various contemplated embodiments, the switch636 may be configured to interrupt electrical connectivity of thebattery, the control circuit, or both.

According to an exemplary embodiment, the starter system includes aninterface, such as a button 634 on the receiving port 626. The button634 faces outward and is accessible when the battery 622 is seated inthe receiving port 626. In some embodiments, the interface may be usedto initiate charging of the battery or another function. In otherembodiments, the interface allows the operator to start the engine viathe starter system. For example, the starter system may be configuredsuch that it starts the engine when the button is pushed or when thebutton is pushed and held for a predetermined length of time. In otherembodiments, the starter system may be configured such that it startsthe engine when the button is pushed in combination with another input.For example, the starter system may be configured to start the enginewhen the button is pushed while the bail is engaged or when the bail isengaged within a predetermined time period after the button is pushed.In this way, the button acts as a “start enable” button rather than a“start button.” In some embodiments, the battery or the receiving portincludes a disable button or switch that must be in the on positionbefore the start button can be used to start the engine. The disablebutton can electrically, mechanically, or both electrically andmechanically, prevent the start button from being used to start theengine.

According to an exemplary embodiment, the battery 622 and the receivingport 626 are positioned proximate to the air intake 620 in a locationsimilar to that of a manual recoil starter. Such a positioning allows auser familiar with a manual recoil starter to intuitively start theengine via the starter system by actuating the button 634 or otherinterface device. Eliminating the recoil starter reduces the engineoperating temperature (e.g., the oil temperature) by improving air flowinto the cooling system (e.g., the blower housing). For example,replacing the recoil starter with the battery 622 and the receiving port626 can reduce the engine operating temperature by between 10 and 20degrees Fahrenheit (5.6 degrees and 11.1 degrees Celsius) in expectedoperating conditions. Reducing the engine operating temperature can helpto reduce oil deterioration, overheating, and other failure modesrelated to high temperatures.

According to other exemplary embodiments, the battery 622 and thereceiving port 626 may be positioned elsewhere on the engine 610 or onthe outdoor power equipment powered by the engine 610 so that thebattery and the receiving port 626 are accessible to the user and do notinterfere with the normal operation of the engine 610 or the outdoorpower equipment. For example, the battery 622 and the receiving port maybe positioned on the engine housing or the blower housing (e.g., on afaceplate or other portion of the housing). For example, if the engine610 powers a lawn tractor or riding lawn mower, the battery 622 and thereceiving port 626 may be positioned on the dash. If the engine 610powers a snow thrower, the battery 622 and the receiving port 626 may bepositioned on the control panel. A cover or guard may be provided overthe battery 622 to shield the battery 622 from environmental hazardssuch as dust, grass clippings, branches, snow, rain, other moisture,etc. The cover may be permanent, hinged or pivotable relative to a baseor mount, and/or physically removable from a mount.

Referring now to FIGS. 48-58, the battery is shown according to anexemplary embodiment as battery 800 coupled to a battery receiver 802.In the illustrated embodiments, the battery receiver 802 is configuredas a cover or screen of an engine. In some embodiments, the screen ispositioned in an air path of the engine (e.g., at the air intake 620)such that the air drawn into the engine is utilized to cool the battery800 coupled to the receiver 802. In other embodiments, the batteryreceiver 802 takes other shapes or forms appropriate to the location onthe engine or outdoor power equipment to which it is mounted. Accordingto an exemplary embodiment, the battery 800 engages the receiver 802with a sliding connection (e.g., a pin or blade connection), allowingthe battery 800 to engage and disengage the receiver 802 or anotherdevice such as a charging station without the use of tools, as would beneeded with screw terminals. Rails 804 on the receiver 802 are receivedin corresponding slots or grooves 806 provided in the battery 800. Alocking mechanism, shown as a pair of latches 808 (e.g., hooks, arms,etc.) are biased in an outward direction and are configured to snap intoplace in apertures 810 when the battery 800 is inserted into thereceiver 802 to hold the battery 800 in the receiving receptacle or port842. The locking mechanism is released by disengaging the latches 808from the apertures 810. According to an exemplary embodiment, thelatches 808 are coupled to buttons 812 on the side of the battery 800.Pressing the buttons retracts the latches 808 from the apertures 810 andallows the battery 800 to be removed from the receiver 802.

Referring now to FIGS. 48-53, the battery 800 is shown. The battery 800includes one or more electrochemical cells 816 electrically coupledtogether. In a preferred embodiment the cells 816 are lithium-ion cellsand the battery 800 is considered to be a lithium-ion battery. The cells816 are contained within a housing 814 and are coupled to terminals(e.g., male terminals or female terminals) and/or to internal circuitry(e.g., for an electric start system as described elsewhere in theapplication), shown in FIG. 53 as a printed circuit board 818 within thehousing 814. According to an exemplary embodiment, the battery 800further includes a display, shown as an LCD display 820. The lithium-ionbattery 800 is not equivalent to a lithium-ion battery for use withcordless power tools (e.g., a drill). For example, the battery 800 mayinclude fewer cells than a power tool battery and is intended for lessfrequent cycling at lower run times than a power tool battery (e.g.,used to start an engine, not used to power frequent running of a drillmotor for relatively long durations).

The housing 814 is a sealed enclosure that is configured to protect theelectrochemical cells by preventing environmental contaminants (e.g.,moisture, plant debris, salt, dust, etc.) from passing into the interiorof the battery 800. The housing 814 provides a rugged structure that isable to withstand impact during operation of the outdoor powerequipment, such as from branches. The housing 814 is formed from amaterial that is resistant to liquid or vaporized fuel (e.g.,polyethylene terephthalate or PET) to prevent fuel from passing into theinterior of the battery 800. The housing 814 includes a forward, firstportion 822 and rearward, second portion 824. The slots 806 are providedon the first portion 822 and the latches 808 and the buttons 812 areprovided on the second portion 824. The lower surface of the housing 814includes a shoulder 826 separating the first portion 822 from the secondportion 824. The shoulder 826 contacts the receiver 802 to provide amechanical stop that limits the travel of the battery 800 relative tothe receiver 802. When the battery 800 is fully seated within thereceiver 802, the second portion 824 remains partially protruding beyondthe surface of the receiver 802 such that the buttons 812 are accessibleby a user.

According to an exemplary embodiment, the terminals may extend from theunderside of the housing 814 proximate the shoulder 826. The terminalsare configured to interface with corresponding terminals in the receiver802 to electrically couple the cells 816 to the starter system or toanother device, such as a charging station.

Referring to FIGS. 50 and 52, according to an exemplary embodiment, thebattery 800 includes a pair of primary terminals 830 that electricallycouple the cells 816 to another system, such as the starter system. Theprimary terminals 830 may be positioned in a parallel arrangement, asshown in FIGS. 50 and 52. In other exemplary embodiments, the primaryterminals 830 may be arranged perpendicular to each other or may bepositioned in a coaxial arrangement (e.g., provided on the end face ofthe battery 800 instead of on the bottom face of the battery 800).

The battery 800 further includes one or more auxiliary terminals 832.The auxiliary terminals 832 provide a means for the battery 800 tocommunicate with other systems of the engine. For example, the auxiliaryterminals may be configured to couple the internal circuitry of thebattery 800 to sensors and other external systems to monitor and/orcontrol the external systems (e.g., detecting the position of the bailor the brake, sensing vibration of the engine or vacuum strength in thecarburetor, etc.). While the battery 800 is shown as including a singleauxiliary terminal 832, in other exemplary embodiments the battery 800may include two or more auxiliary terminals 832. The battery 800 mayfurther include additional auxiliary terminals that may be adapted forfuture uses (e.g., communication with or connection to additional inputsincluding sensors, other devices, controllers, etc. and/or communicationwith or connection to outputs including user interfaces, monitors,speakers, alarms, lights, indicators, etc.). The terminals 830 and 832are configured to withstand the vibrations associated with an engine andwith outdoor power equipment so that the vibrations do not break anyelectrical connections to the terminals 803 and 832.

According to an exemplary embodiment, the number and positioning of theterminals 830 and 832 on the battery 800 is fixed for batteries ofvarying size (e.g., voltage capacity or number of cells). As shown inFIG. 53, according to one exemplary embodiment, the battery 800 mayinclude four cells 816. Batteries of different capacities (e.g.different voltage capacities including 1V, 3V, 6V, 12V, 18V, etc.) maytherefore have a common interface structure (e.g., the number andpositioning of the terminals 830 and 832 is fixed). For example,according to other exemplary embodiments, a battery intended for usewith a walk-behind lawnmower may include only three cells while abattery intended for use with a riding lawnmower may include six cells.The housings of the battery and the receiver may be configured to allowonly batteries of a desired capacity to be coupled to a specificreceiver. According to another exemplary embodiment the housings of thebattery and the receiver may be configured such that a larger capacitybattery may be used with a smaller capacity receiver on equipment thatis capable of operating using a smaller capacity battery (e.g., a sixcell riding lawnmower battery being used on a walk-behind mower as anextended life battery), but a smaller capacity battery is incapable ofbeing used with a larger capacity receiver on a machine that isconfigured to use a larger capacity battery. For example, the“footprint” or perimeter shape of the battery 800 as seen from below(FIG. 50) would remain the same for the larger capacity battery as forthe smaller capacity battery, but the larger capacity batter would betaller. In this way, the larger capacity battery would be able to engagethe receiver for the smaller capacity battery, but features (e.g.,grooves, ridges, flanges, detents, etc.) on the smaller capacityreceiver and on the larger capacity battery would only allow the largercapacity battery to engage the receiver for the larger capacity battery,the features on this larger capacity receiver and the lack ofcorresponding features on the smaller capacity battery would prevent thesmaller capacity battery from being used with the larger capacityreceiver. The features on the larger capacity receiver act as a lockoutpreventing the use of the smaller capacity battery with the largercapacity receiver.

According to other exemplary embodiments, the battery 800 may furtherinclude additional ports or connectors. For example, the battery mayinclude a universal serial bus (USB) port coupled to the cells 816 andor/the internal circuitry 818. The USB port may be used as an input toreceive power to charge the cells 816 or as an output to power or chargeanother device (e.g., a mobile phone, etc.) from the cells 816.

Referring now to FIGS. 54-58, the battery receiver 802 is shown. Thebattery receiver 802 is a dome-shaped body that is configured as a coveror screen of an engine. The receiver 802 includes a multitude ofopenings shown as slots 840 to allow air to pass through the receiver802 while limiting the ability for debris such as grass clippings topass through the receiver 802. The battery 800 is received in areceptacle 842 defined by a floor 844 and sidewalls 846. The receptacle842 is open on one end 848 to allow the battery 800 to be slid into thereceptacle 842 from the side. According to an exemplary embodiment, thesidewalls 846 are connected by an arcuate end wall 845. The rails 804extend inward from the sidewalls 846. According to another exemplaryembodiment, the rails 804 may form a single unitary body that continuesalong the arcuate end wall. In other embodiments, the receptacle 842 isincorporated into a receiver having a different shape or formappropriate to its mounting location on an engine or outdoor powerequipment. In a preferred embodiment, the battery receiver 802 ismounted to an air-cooled small internal combustion engine (e.g., of lessthan 10 hp (7.5 kW), under 225 cc displacement) at the locationtypically occupied by a recoil starter. In this way the battery receiver802 and battery 800 can be used to implement an electronic start systemin place of the typical recoil starter system.

As shown in FIG. 55, the sidewalls 846 may include angled end portions847 proximate the open end 848 such that the open end 848 has a widththat is greater than the width of the battery 800 and of the remainderof the receptacle 842. The angled portions 847 facilitate the insertionof the battery 800 into the receptacle 842 through the widened open end848.

The floor 844 is an offset body with a vertical step or shoulder 850that contacts the shoulder 826 to limit the travel of the battery 800relative to the receiver 802. The apertures 810 in the sidewalls 846receive the outwardly biased latches 808 protruding from the battery 800when the shoulder 826 on the battery 800 contacts the shoulder 850 onthe receiver 802. The engagement of the latches 808 in the apertures810, the engagement of the rails 804 in the slots 806, and the contactof the shoulders 826 and 850 cooperate to retain the battery 800 in thereceiver 802 and minimize the play between the battery 800 and thereceiver 802 to maintain contact between the terminals on the battery800 and the terminals on the receiver 802.

The battery receiver 802 includes a pair of primary terminals 860 thatare aligned with the primary terminals 830 of the battery 800. Accordingto an exemplary embodiment, the primary terminals 860 are blade orplate-like members positioned in a parallel arrangement, as shown inFIG. 55. In other exemplary embodiments, the primary terminals 860 maybe arranged perpendicular to each other or may be positioned in acoaxial arrangement (e.g., provided on an end face such as the arcuateend wall 845 or the shoulder 850 of the receptacle 842).

The receiver 802 further includes one or more auxiliary terminals 862that are aligned with the auxiliary terminals 832 of the battery 800.While the receiver 802 is shown as including a single auxiliary terminal862, in other exemplary embodiments the receiver 802 may include two ormore auxiliary terminals 862. The receiver 802 may further includeadditional auxiliary terminals that may be adapted for future uses.These additional terminals correspond to similar additional terminals onthe battery 800 and cooperate with the additional terminals of thebattery and may be adapted for future use. The terminals 860 and 862 areconfigured to withstand the vibrations associated with an engine andwith outdoor power equipment so that the vibrations do not break anyelectrical connections to the terminals 860 and 862.

As shown in FIGS. 57-58, the terminals of the receiver 802 (e.g., theprimary terminals 860 and the auxiliary terminal 862) are shaped toextend through the body of the receiver 802. According to an exemplaryembodiment, the terminals include a first, upwardly extending portion864, a second, downwardly extending portion 866, and a connectingportion 868. The first extending portion 864 protrudes from the floor844 proximate the shoulder 850 and each are positioned such that theycontact the terminals of the battery 800 when the battery 800 is seatedin the receiver 802. The second extending portion 866 protrudes from theunderside of the receiver 802. The second extending portion may beconductively coupled to an electrical system powered by the battery 800,such as the starter system, such as with a wiring harness. Theconnecting portion 868 extends between the first portion 864 and thesecond portion 866. According to an exemplary embodiment, the connectingportion 868 is positioned within ribs 865 on the underside of thereceiver 802 to minimize the amount of the terminal that is exposed.

According to an exemplary embodiment, the terminals may be positionedsuch that they are protected from environmental hazards. For example,the floor 844 may slope downward from the terminals to direct moistureaway from the terminals. According to other exemplary embodiments, theterminals may be oriented horizontally or the terminals of the batterymay be vertical and interface with terminals provided in an elevatedportion of the receiver such that any moisture that enters the spacebetween the battery and the receiver flows away from the terminals. Thereceiver and/or the portion of the engine proximate the receiver mayinclude features (e.g., channels, drain holes, weep holes, slopedsurfaces, etc.) that direct moisture and debris away from the terminals.

According to an exemplary embodiment, the electrical control circuitsare each configured provide hard-wired logic for a starter systemaccording to the disclosure provided herein. In some embodiments, eachcircuit contains essentially all analog parts. In some embodiments, eachcircuit or another such circuit is configured to detect when the bailcloses (or opens) a switch (see, e.g., switch 518 as shown in FIG. 43).In other embodiments, a circuit is configured to sense when the brake ispulled and then to enable ignition of the engine. In other contemplatedembodiments, a circuit may be further configured to sense vibration ofthe engine or Venturi vacuum strength in the carburetor, and cut powerto the motor when the associated information indicates that the engineis running.

According to an exemplary embodiment, the circuits may be contained on acircuit board (or circuit boards) within the housing of the energystorage device, such as the battery 800 as shown in FIG. 53, and may befully powered by the battery or other on-board source. As is known,rechargeable batteries generally have integrated circuitry containedtherein that is configured to monitor operating variables of the battery(e.g., current, voltage, etc.) related to its charge state. Thus, theaddition of the circuits of to the existing circuit board(s) or on anadditional circuit may require no electrical interface to components ofthe lawn mower or other outdoor power equipment, and no additionalwiring or hook ups are necessary. Accordingly, the assembly process forthe associated outdoor power equipment may be simplified and improved.According to another exemplary embodiment, the circuits may instead beadded to the battery receiver, such as the receiver 802, to reduce thecost of the battery, or to other electrical components of the engine oroutdoor power equipment (e.g., a controller, control circuitry, printedcircuit board, etc.). This may help to reduce the cost of individualbatteries 800 be eliminating some of the circuitry that might otherwisebe present in the battery. Furthermore, the circuits are only exemplary,and the specifics of the circuitry may be altered to optimize theintegration of their functionality onto the existing circuit board(s) oradditional circuit board(s) within the battery.

A circuit may be further configured to monitor the operation of theengine and/or the state of the battery to predict the number of startscapable with the battery. For example, a circuit may monitor the stateof charge of the battery, the average amount of power expended to startthe engine, and/or other characteristics of the engine (e.g., run state,rpms, etc.). The average amount of power expended to start the engineand/or characteristics of the engine may be communicated to the circuitthrough one or more of the terminals (e.g., the auxiliary terminal 832shown in FIG. 50 and the auxiliary terminal 862 shown in FIG. 55)coupling the battery to engine via the receiver. The number of startscapable with the battery may then be shown on a display integrated intothe battery (e.g., the display 820 shown in FIG. 49) or a displayprovided elsewhere, such as on the receiver, on the engine, on a controlpanel, or on the dash. The number of starts capable with the battery maybe calculated based on the characteristics of the engine, for example, abattery having a specific charge may be able to perform more starts on asmaller engine (e.g., for a walk-behind mower) than for a larger engine(e.g., for a ride-on tractor) or be able to perform more starts for onetype of outdoor power equipment (e.g., a pressure washer) than foranother type of outdoor power equipment (e.g., a lawn mower).

A circuit may be further configured to monitor other characteristics ofthe engine or the outdoor power equipment powered by the engine bycommunicating with sensors and monitoring devices (e.g., fluid levelsensors, temperature sensors, pressure sensors, chronometers, fuelquality sensors, tachometers, etc.). The circuit may output data relatedto the information received from the sensors and monitoring devices to adisplay, such as the display 820 integrated into the battery 800 or adisplay integrated into the receiver 802. The display may thereforecommunicate to the user of the outdoor power equipment variousoperational data related to the outdoor power equipment, the engine, andthe battery. For example, the circuit may output to the displayinformation such as fuel level, oil level, operational time, fuelquality, or battery temperature. The display may be used instead of orin addition to other displays, such as dashboard or control paneldisplays. Additionally, the circuit may monitor the temperature of thebattery via an input from a temperature sensor. Temperature monitoringcan be used to alert the user (e.g., via the display 820) if the batterytemperature is too low for normal use of the battery. Using the battery800 to power these circuits allows information to be provided to theuser (e.g., battery temperature, fuel level, oil level, the presence ofbad fuel) prior to the engine being started so that any issues can beaddressed before attempting to start the engine.

Referring now to FIG. 59, a pressure washer system 2010 includes theengine 610 of FIG. 4. To start the engine 610, an operator may press thebutton 634 shown in FIGS. 46-47. In some such embodiments, braking ofthe system may occur via an ignition interrupt that prevents sparks fromigniting fuel and air in a combustion chamber of the engine 610.Resistance provided by the water pump of the pressure washer system 2010then slows (i.e., brakes) the engine 610. In other contemplatedembodiments, an engine of a portable generator may use a similar startersystem and battery 622, as well as a similar braking system. Powerprovided by the generator may be used to charge the battery 622 of thestarter system.

As pressure washer system 2010 does not have a bail similar to bails126, 212, 312 shown in FIG. 41, the switch that makes up push button 634of the pressure washer system 2010 may be more complex than that used inlawnmower applications utilizing a bail. That is, in lawnmowerconfigurations shown above, a single-pole-single-throw switch is used tosend 12 V to power up and start the engine when the user pulls the bail,and then removes the 12 V and shorts the ignition to ground when theuser releases the bail, thus stopping the engine. However, on non-mowerapplications that do not use a bail, a double-pole-double-throw switchmay be used, which grounds the ignition on one pole when in the OFFposition, and sends 12 V to the second pole when in the ON position. Inthis way, one position removes the 12 V and shorts the ignition (OFF),while the other position un-shorts the ignition and applies the 12 V(ON).

As an alternative to the push-button starter systems described above,and in accordance with another exemplary embodiment, engine 610 of thepressure washer system 2010 may be started via actuation of a trigger2002 on a spray wand 2004. An example circuitry schematic in accordancewith the proposed embodiment is illustrated in FIG. 60. Block 2102 shownin FIG. 60 represents starter system circuitry. The present embodimentrelated to pressure washer system 2010 requires additional circuitry tofunction effectively. For instance, block 2104 acts as a starter motorcranking limiter, which limits the amount of time the starter motor cancrank without the engine starting. Block 2106 represents a flow switch,which senses water flow through the system, as will be discussed furtherherein. Block 2108 represents an ON time delay circuit, which detectsthe amount of time that a user has actuated trigger 2012 and preventsstarting of the engine if a predetermined time period has not elapsed(e.g., during incidental user contact with trigger 2002). Block 2110, onthe other hand, represents an OFF time delay circuit, which allows theengine to continue running for a predetermined period of time after theuser has released trigger 2002. Block 2110 may contain an output to adevice (e.g., a potentiometer) which allows for user customization ofthe OFF time delay. Block 2112 represents a manual stop override input(e.g., via an enable key insert) for the OFF time delay, which allows auser to entirely deactivate the OFF time delay and allow the engine tocontinue running beyond any predetermined time limit after the user hasreleased trigger 2002. Finally, block 2114 represents circuitry thatsenses if the starter motor pinion gear has disengaged from the engine'sflywheel gear while the starter motor is cranking so as to prevent thestarter motor from stopping the cranking operation prior to the enginebeing started. The overall operation of the starter system representedby the circuitry shown in FIG. 60 will be discussed herein.

Prior to operation of pressure washer system 2010, spray wand 2004 mustbe connected to a water pump via a hose, wherein the water pump is alsoconnected to a water source via another hose. With the water sourceconnected to the water pump, actuation of trigger 2002 causes at least asmall amount of water to flow through the water pump, regardless ofwhether or not engine 610 is operating. A flow switch and/or pressureswitch is used to sense the flow of water or pressure change whentrigger 2002 is actuated. A flow switch, either self-contained orintegrated within the pump, may be placed between the water source andthe pump inlet (i.e., the low pressure side) or between the pump outletand the spray wand (i.e., the high pressure side). If pressure sensingis used, pressure switches may be located at both the pump inlet and theoutlet. Alternatively, a single pressure differential switch may beused. From the sensed flow or pressure change, engine 610 can be startedusing the same logic as the push-button starter system described inprevious embodiments. Alternatively, a sensor or switch could bedirectly engaged by actuation of trigger 2002 to start engine 610,wherein the electrical connection between such a sensor or switch mayrun between trigger 2002 and engine 610 along or through the spray wandhose. Alternatively, a sensor or switch could be directly engaged byactuation of trigger 2002 to start engine 610, wherein wirelesscommunication is used between trigger 2002 and engine 610 via radiofrequency (RF) or Infrared (IR).

During connection of the water source to the pump and subsequent fillingof the pump, a flow switch and/or pressure switch may sense ashort-duration flow of water or a pressure change before the trigger2002 is actuated. Therefore, it may not be desirable for engine 610 tostart immediately upon sensing inlet flow or pressure change. Instead, atimed delay start (e.g., 1-3 seconds) could be provided by the startersystem circuitry described above, wherein the timed delay could beestablished via resistor-capacitor circuit (RC circuit) or equivalent.The start timed delay would eliminate the possibility of unintentionalengine starting.

Similarly, it may not be desirable for engine 610 to stop (i.e., turnoff) immediately upon user release of trigger 2002. Instead, a timeddelay (e.g., 1-2 minutes) could be provided by the starter systemcircuitry described above, wherein the timed delay could be determinedby counting engine ignition pulses after release of trigger 2002 orestablished via a resistor-capacitor circuit (RC circuit) or equivalent.If an RC circuit is used, a user-adjustable timed delay stop could beprovided if a variable resistor (i.e., rheostat) is used. In this way,engine 610 is not unnecessarily shut down when the user only brieflyreleases trigger 2002, thereby avoiding overly-frequent restarts ofengine 610 during operation. Such a timed delay stop could also be usedin combination with an automatic throttle control mechanism to lowerengine speed and reduce noise and fuel consumption during the timeddelay. If the user wishes to shut down engine 610 before the timed delayperiod expires, it is also envisioned that a manual stop switch (notshown) could be added to engine 610. Similarly, a manual start switch(not shown) could also be added to engine 610 to serve as an optional orback-up start system to the trigger-actuated engine starting system.

An additional advantage of the timed delay stop feature is potentialelimination of the need for a thermal bypass system in the pump. Inconventional pressure washer systems, when the trigger is released whilethe engine is running, the water in the pump recirculates underpressure. This condition causes the recirculating water in the pump tobecome increasingly hot over time. Excessively hot water may causepermanent damage to the pump components. To resolve this problem, mostconventional pressure washers are equipped with a thermal bypass system.When the water temperature reaches a critical temperature (typically 140degrees Fahrenheit (60 degrees Celsius)), the thermal bypass systembleeds the high temperature water out of the pump and to the ground.After cool water enters the pump and reduces the recirculating watertemperature, the thermal bypass system halts the hot water bleed-off. Ifthe timed delay stop described above is set shorter than the timerequired for the recirculating water in the pump to reach criticalbleed-off temperature (typically 90 seconds), then a thermal bypasssystem would not necessarily be required.

Another advantage of the trigger-actuated engine starting systemdescribed above may be a decreased reliance on a pressure-relievingunloader valve during engine start-up. In conventional pressure washersystems, the water source is provided to the water pump prior to enginestart-up and before the spray wand's trigger is actuated, creating apressure within the water pump that must be relieved by an unloadervalve in order to ease engine starting. However, with thetrigger-actuated engine system described above, this unloader valvecould be downsized or entirely eliminated, as the trigger actuationitself relieves the water pressure built up within the water pump (viainitiating water flow) prior to the engine being started.

Yet another advantage of the trigger-actuated engine starting systemdescribed above may be decreased pump damage caused by a user manuallystarting the pump without the water source connected to the pump inlet.In conventional pressure washer systems, the engine can be manuallystarted regardless of whether or not the operator has connected thewater source to the pump inlet. If the pump is run without a watersupply, the pump will be permanently damaged in a short period of time(typically 30 sec) due to high internal friction and temperatures. Usingthe trigger-actuated starting system described above, the engine cannotbe started unless a water source is connected to the pump inlet, aswater flow must be sensed by a flow or pressure switch to enablestarting.

In accordance with the embodiment described above, a trigger-actuatedengine starting system may reduce fuel consumption and eliminate noisegenerated by a gas pressure washer system when not in use, as needlessengine operation can be avoided when the user is not directly activatingthe trigger 2002 to spray water.

The various control systems and circuits described herein (including inthe related applications incorporated by reference) may be implementedas “non-programmable circuitry” that consists of analog or digital hardcircuitry that does not utilize a microcontroller or software or as acontroller, microcontroller, computer, or other programmable device. Itis believed that embodiments in which the controls are implemented asnon-programmable circuitry including discrete components may be lessexpensive than embodiments implemented with microcontrollers or usingsoftware. Such non-programmable circuitry embodiments do not include amicrocontroller. The various control systems and circuits describedherein (including in the related applications incorporated by reference)may be implanted as a component of a battery, as a component of abattery receiver or receiving port, as a component of the engine, as acomponent of a starter module separate from the engine, and/or as acomponent of the outdoor power equipment.

The construction and arrangements of the starter system for an engine,as shown in the various exemplary embodiments, are illustrative only.Although only a few embodiments have been described in detail in thisdisclosure, many modifications are possible (e.g., variations in sizes,dimensions, structures, shapes and proportions of the various elements,values of parameters, mounting arrangements, use of materials, colors,orientations, etc.) without materially departing from the novelteachings and advantages of the subject matter described herein. Someelements shown as integrally formed may be constructed of multiple partsor elements, the position of elements may be reversed or otherwisevaried, and the nature or number of discrete elements or positions maybe altered or varied. The order or sequence of any process, logicalalgorithm, or method steps may be varied or re-sequenced according toalternative embodiments. Other substitutions, modifications, changes andomissions may also be made in the design, operating conditions andarrangement of the various exemplary embodiments without departing fromthe scope of the present invention.

What is claimed is:
 1. An electric starting system for an internalcombustion engine, comprising: a rechargeable battery including abattery housing, internal circuitry housed within the battery housing,two voltage output terminals, and an enable terminal; a battery receiverincluding a battery receptacle configured to receive the rechargeablebattery, two voltage output terminals, and the enable terminal; and astarter motor configured to start the internal combustion engine;wherein the internal circuitry is coupled to the enable terminal andconfigured to enable and disable an internal switch to provide power toone of the two voltage output terminals, the internal circuitrymonitoring at least one internal condition of the rechargeable batteryfor a fault condition; wherein the internal circuitry disables theinternal switch upon detection of the fault condition.
 2. The electricstarting system of claim 1, wherein the fault condition comprises anovervoltage condition of the rechargeable battery.
 3. The electricstarting system of claim 1, wherein the fault condition comprises anundervoltage condition of the rechargeable battery.
 4. The electricstarting system of claim 1, wherein the fault condition comprises anovercurrent condition of the rechargeable battery.
 5. The electricstarting system of claim 1, wherein the fault condition comprises anovertemperature condition of the rechargeable battery.
 6. The electricstarting system of claim 1, further comprising an external switchpositioned outside the battery housing and provided in series betweenone of the two voltage output terminals of the battery receiver and theenable terminal of the battery receiver to allow a user to selectivelyenable and disable the rechargeable battery; wherein the internalcircuitry disables the internal switch and overrides the external switchupon detection of the fault condition.
 7. The electric starting systemof claim 6, further comprising a user interface device for manuallyactuating the external switch.
 8. The electric starting system of claim6, further comprising a sensor for automatically actuating the externalswitch.
 9. The electric starting system of claim 1, wherein theterminals of the rechargeable battery comprise female terminals and theterminals of the battery receiver comprise male terminals.
 10. Theelectric starting system of claim 1, wherein the rechargeable battery isconfigured to be selectively attached to and removed from the batteryreceiver without tools.
 11. Outdoor power equipment, comprising: aninternal combustion engine; a rotating tool coupled to the engine; arechargeable battery including a battery housing, internal circuitryhoused within the battery housing, two voltage output terminals, and anenable terminal; a battery receiver including a battery receptacleconfigured to receive the rechargeable battery, two voltage outputterminals, and the enable terminal; and a starter motor configured tostart the internal combustion engine; wherein the internal circuitry iscoupled to the enable terminal and configured to enable and disable aninternal switch to provide power to one of the two voltage outputterminals, the internal circuitry monitoring at least one internalcondition of the rechargeable battery for a fault condition; wherein theinternal circuitry disables the internal switch upon detection of thefault condition.
 12. The outdoor power equipment of claim 11, whereinthe fault condition comprises an overvoltage condition of therechargeable battery.
 13. The outdoor power equipment of claim 11,wherein the fault condition comprises an undervoltage condition of therechargeable battery.
 14. The outdoor power equipment of claim 11,wherein the fault condition comprises an overcurrent condition of therechargeable battery.
 15. The outdoor power equipment of claim 11,wherein the fault condition comprises an overtemperature condition ofthe rechargeable battery.
 16. The outdoor power equipment of claim 11,further comprising an external switch positioned outside the batteryhousing and provided in series between one of the two voltage outputterminals of the battery receiver and the enable terminal of the batteryreceiver to allow a user to selectively enable and disable therechargeable battery; wherein the internal circuitry disables theinternal switch and overrides the external switch upon detection of thefault condition.
 17. The outdoor power equipment of claim 16, furthercomprising a user interface device for manually actuating the externalswitch.
 18. The outdoor power equipment of claim 16, further comprisinga sensor for automatically actuating the external switch.
 19. Theoutdoor power equipment of claim 11, wherein the terminals of therechargeable battery comprise female terminals and the terminals of thebattery receiver comprise male terminals.
 20. The outdoor powerequipment of claim 11, wherein the rechargeable battery is configured tobe selectively attached to and removed from the battery receiver withouttools.